---
_id: '10692'
abstract:
- lang: eng
text: We experimentally investigate narrow and topologically nontrivial moiré minibands
hosted by van der Waals heterostructures consisting of a graphene monolayer rotationally
faulted with respect to a Bernal-stacked bilayer. At fillings ν= 1 and 3 electrons
per moiré unit cell within these bands, we observe quantized anomalous Hall effects
with Rxy≈h/2e2, indicative of spontaneous polarization of the system into a single
valley-projected band with Chern number C= 2. Remarkably, we also observe the
evidence of symmetry broken Chern insulator states at ν= 1.5 and 3.5. At ν= 3
we find that the sign of the quantum anomalous Hall effect can be reversed via
field-effect control of the chemical potential. This curious effect arises from
the magnetization contribution due to topological edge states, which drive a reversal
of the total magnetization and thus a switch of the favored magnetic state. Remarkably,
we find that this switch is hysteretic, which we use to demonstrate non-volatile
electric-field-induced reversal of the magnetic state. Voltage control of magnetic
states can be used to electrically pattern nonvolatile magnetic domain structures
hosting chiral edge states, with applications ranging from reconfigurable microwave
circuit elements to ultra-low-power magnetic memory.
alternative_title:
- Bulletin of the American Physical Society
article_number: E42.00010
article_processing_charge: No
author:
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Jihang
full_name: Zhu, Jihang
last_name: Zhu
- first_name: Manish
full_name: Kumar, Manish
last_name: Kumar
- first_name: Yuxuan
full_name: Zhang, Yuxuan
last_name: Zhang
- first_name: Fangyuan
full_name: Yang, Fangyuan
last_name: Yang
- first_name: Charles
full_name: Tschirhart, Charles
last_name: Tschirhart
- first_name: Marec
full_name: Serlin, Marec
last_name: Serlin
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: Takashi
full_name: Tanaguchi, Takashi
last_name: Tanaguchi
- first_name: Allan
full_name: MacDonald, Allan
last_name: MacDonald
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
citation:
ama: 'Polshyn H, Zhu J, Kumar M, et al. Orbital Chern insulator states in twisted
monolayer-bilayer graphene and electrical switching of topological and magnetic
order. In: APS March Meeting 2021. Vol 66. American Physical Society; 2021.'
apa: 'Polshyn, H., Zhu, J., Kumar, M., Zhang, Y., Yang, F., Tschirhart, C., … Young,
A. (2021). Orbital Chern insulator states in twisted monolayer-bilayer graphene
and electrical switching of topological and magnetic order. In APS March Meeting
2021 (Vol. 66). Virtual: American Physical Society.'
chicago: Polshyn, Hryhoriy, Jihang Zhu, Manish Kumar, Yuxuan Zhang, Fangyuan Yang,
Charles Tschirhart, Marec Serlin, et al. “Orbital Chern Insulator States in Twisted
Monolayer-Bilayer Graphene and Electrical Switching of Topological and Magnetic
Order.” In APS March Meeting 2021, Vol. 66. American Physical Society,
2021.
ieee: H. Polshyn et al., “Orbital Chern insulator states in twisted monolayer-bilayer
graphene and electrical switching of topological and magnetic order,” in APS
March Meeting 2021, Virtual, 2021, vol. 66, no. 1.
ista: 'Polshyn H, Zhu J, Kumar M, Zhang Y, Yang F, Tschirhart C, Serlin M, Watanabe
K, Tanaguchi T, MacDonald A, Young A. 2021. Orbital Chern insulator states in
twisted monolayer-bilayer graphene and electrical switching of topological and
magnetic order. APS March Meeting 2021. APS: American Physical Society, Bulletin
of the American Physical Society, vol. 66, E42.00010.'
mla: Polshyn, Hryhoriy, et al. “Orbital Chern Insulator States in Twisted Monolayer-Bilayer
Graphene and Electrical Switching of Topological and Magnetic Order.” APS March
Meeting 2021, vol. 66, no. 1, E42.00010, American Physical Society, 2021.
short: H. Polshyn, J. Zhu, M. Kumar, Y. Zhang, F. Yang, C. Tschirhart, M. Serlin,
K. Watanabe, T. Tanaguchi, A. MacDonald, A. Young, in:, APS March Meeting 2021,
American Physical Society, 2021.
conference:
end_date: 2021-03-19
location: Virtual
name: 'APS: American Physical Society'
start_date: 2021-03-15
date_created: 2022-01-27T09:49:48Z
date_published: 2021-03-01T00:00:00Z
date_updated: 2022-01-27T10:46:23Z
day: '01'
extern: '1'
intvolume: ' 66'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR21/Session/E42.10
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2021
publication_identifier:
issn:
- 0003-0503
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Orbital Chern insulator states in twisted monolayer-bilayer graphene and electrical
switching of topological and magnetic order
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 66
year: '2021'
...
---
_id: '10616'
abstract:
- lang: eng
text: Electrons in moiré flat band systems can spontaneously break time-reversal
symmetry, giving rise to a quantized anomalous Hall effect. In this study, we
use a superconducting quantum interference device to image stray magnetic fields
in twisted bilayer graphene aligned to hexagonal boron nitride. We find a magnetization
of several Bohr magnetons per charge carrier, demonstrating that the magnetism
is primarily orbital in nature. Our measurements reveal a large change in the
magnetization as the chemical potential is swept across the quantum anomalous
Hall gap, consistent with the expected contribution of chiral edge states to the
magnetization of an orbital Chern insulator. Mapping the spatial evolution of
field-driven magnetic reversal, we find a series of reproducible micrometer-scale
domains pinned to structural disorder.
acknowledgement: 'We thank A. H. Macdonald, J. Zhu, M. Zaletel, and D. Xiao for discussions
of the results and E. Lachman for comments on the manuscript. Funding: The work
was primarily funded by the US Department of Energy under DE-SC0020043, with additional
support for instrumentation development supported by the Army Research Office under
grant W911NF-16-1-0361. K.W. and T.T. acknowledge support from the Elemental Strategy
Initiative conducted by MEXT, Japan, grant JPMXP0112101001; JSPS KAKENHI grant JP20H00354
and CREST grant JPMJCR15F3, JST. C.L.T. acknowledges support from the Hertz Foundation
and from the National Science Foundation Graduate Research Fellowship Program under
grant 1650114. This project is funded in part by the Gordon and Betty Moore Foundation’s
EPiQS Initiative, grant GBMF9471 to A.F.Y.'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: C. L.
full_name: Tschirhart, C. L.
last_name: Tschirhart
- first_name: M.
full_name: Serlin, M.
last_name: Serlin
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: A.
full_name: Shragai, A.
last_name: Shragai
- first_name: Z.
full_name: Xia, Z.
last_name: Xia
- first_name: J.
full_name: Zhu, J.
last_name: Zhu
- first_name: Y.
full_name: Zhang, Y.
last_name: Zhang
- first_name: K.
full_name: Watanabe, K.
last_name: Watanabe
- first_name: T.
full_name: Taniguchi, T.
last_name: Taniguchi
- first_name: M. E.
full_name: Huber, M. E.
last_name: Huber
- first_name: A. F.
full_name: Young, A. F.
last_name: Young
citation:
ama: Tschirhart CL, Serlin M, Polshyn H, et al. Imaging orbital ferromagnetism in
a moiré Chern insulator. Science. 2021;372(6548):1323-1327. doi:10.1126/science.abd3190
apa: Tschirhart, C. L., Serlin, M., Polshyn, H., Shragai, A., Xia, Z., Zhu, J.,
… Young, A. F. (2021). Imaging orbital ferromagnetism in a moiré Chern insulator.
Science. American Association for the Advancement of Science. https://doi.org/10.1126/science.abd3190
chicago: Tschirhart, C. L., M. Serlin, Hryhoriy Polshyn, A. Shragai, Z. Xia, J.
Zhu, Y. Zhang, et al. “Imaging Orbital Ferromagnetism in a Moiré Chern Insulator.”
Science. American Association for the Advancement of Science, 2021. https://doi.org/10.1126/science.abd3190.
ieee: C. L. Tschirhart et al., “Imaging orbital ferromagnetism in a moiré
Chern insulator,” Science, vol. 372, no. 6548. American Association for
the Advancement of Science, pp. 1323–1327, 2021.
ista: Tschirhart CL, Serlin M, Polshyn H, Shragai A, Xia Z, Zhu J, Zhang Y, Watanabe
K, Taniguchi T, Huber ME, Young AF. 2021. Imaging orbital ferromagnetism in a
moiré Chern insulator. Science. 372(6548), 1323–1327.
mla: Tschirhart, C. L., et al. “Imaging Orbital Ferromagnetism in a Moiré Chern
Insulator.” Science, vol. 372, no. 6548, American Association for the Advancement
of Science, 2021, pp. 1323–27, doi:10.1126/science.abd3190.
short: C.L. Tschirhart, M. Serlin, H. Polshyn, A. Shragai, Z. Xia, J. Zhu, Y. Zhang,
K. Watanabe, T. Taniguchi, M.E. Huber, A.F. Young, Science 372 (2021) 1323–1327.
date_created: 2022-01-13T12:17:45Z
date_published: 2021-05-27T00:00:00Z
date_updated: 2022-01-13T14:11:36Z
day: '27'
doi: 10.1126/science.abd3190
extern: '1'
external_id:
arxiv:
- '2006.08053'
pmid:
- '34045322'
intvolume: ' 372'
issue: '6548'
keyword:
- multidisciplinary
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2006.08053
month: '05'
oa: 1
oa_version: Preprint
page: 1323-1327
pmid: 1
publication: Science
publication_identifier:
eissn:
- 1095-9203
issn:
- 0036-8075
publication_status: published
publisher: American Association for the Advancement of Science
quality_controlled: '1'
scopus_import: '1'
status: public
title: Imaging orbital ferromagnetism in a moiré Chern insulator
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 372
year: '2021'
...
---
_id: '10617'
abstract:
- lang: eng
text: When a flat band is partially filled with electrons, strong Coulomb interactions
between them may lead to the emergence of topological gapped states with quantized
Hall conductivity. Such emergent topological states have been found in partially
filled Landau levels1 and Hofstadter bands2,3; however, in both cases, a large
magnetic field is required to produce the underlying flat band. The recent observation
of quantum anomalous Hall effects in narrow-band moiré materials4,5,6,7 has led
to the theoretical prediction that such phases could be realized at zero magnetic
field8,9,10,11,12. Here we report the observation of insulators with Chern number
C = 1 in the zero-magnetic-field limit at half-integer filling of the moiré superlattice
unit cell in twisted monolayer–bilayer graphene7,13,14,15. Chern insulators in
a half-filled band suggest the spontaneous doubling of the superlattice unit cell2,3,16,
and our calculations find a ground state of the topological charge density wave
at half-filling of the underlying band. The discovery of these topological phases
at fractional superlattice filling enables the further pursuit of zero-magnetic-field
phases that have fractional statistics that exist either as elementary excitations
or bound to lattice dislocations.
acknowledgement: We are grateful to J. Zhu for fruitful discussions. A.F.Y. acknowledges
support from the Office of Naval Research under award N00014-20-1-2609, and the
Gordon and Betty Moore Foundation under award GBMF9471. M.P.Z. acknowledges support
from the ARO under MURI W911NF-16-1-0361. K.W. and T.T. acknowledge support from
the Elemental Strategy Initiative conducted by the MEXT, Japan, via grant no. JPMXP0112101001;
JSPS KAKENHI grant no. JP20H00354; and the CREST(JPMJCR15F3), JST. A.V. was supported
by a Simons Investigator Award. P.L. was supported by the Department of Defense
(DoD) through the National Defense Science and Engineering Graduate Fellowship (NDSEG)
Program.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Y.
full_name: Zhang, Y.
last_name: Zhang
- first_name: M. A.
full_name: Kumar, M. A.
last_name: Kumar
- first_name: T.
full_name: Soejima, T.
last_name: Soejima
- first_name: P.
full_name: Ledwith, P.
last_name: Ledwith
- first_name: K.
full_name: Watanabe, K.
last_name: Watanabe
- first_name: T.
full_name: Taniguchi, T.
last_name: Taniguchi
- first_name: A.
full_name: Vishwanath, A.
last_name: Vishwanath
- first_name: M. P.
full_name: Zaletel, M. P.
last_name: Zaletel
- first_name: A. F.
full_name: Young, A. F.
last_name: Young
citation:
ama: Polshyn H, Zhang Y, Kumar MA, et al. Topological charge density waves at half-integer
filling of a moiré superlattice. Nature Physics. 2021. doi:10.1038/s41567-021-01418-6
apa: Polshyn, H., Zhang, Y., Kumar, M. A., Soejima, T., Ledwith, P., Watanabe, K.,
… Young, A. F. (2021). Topological charge density waves at half-integer filling
of a moiré superlattice. Nature Physics. Springer Nature. https://doi.org/10.1038/s41567-021-01418-6
chicago: Polshyn, Hryhoriy, Y. Zhang, M. A. Kumar, T. Soejima, P. Ledwith, K. Watanabe,
T. Taniguchi, A. Vishwanath, M. P. Zaletel, and A. F. Young. “Topological Charge
Density Waves at Half-Integer Filling of a Moiré Superlattice.” Nature Physics.
Springer Nature, 2021. https://doi.org/10.1038/s41567-021-01418-6.
ieee: H. Polshyn et al., “Topological charge density waves at half-integer
filling of a moiré superlattice,” Nature Physics. Springer Nature, 2021.
ista: Polshyn H, Zhang Y, Kumar MA, Soejima T, Ledwith P, Watanabe K, Taniguchi
T, Vishwanath A, Zaletel MP, Young AF. 2021. Topological charge density waves
at half-integer filling of a moiré superlattice. Nature Physics.
mla: Polshyn, Hryhoriy, et al. “Topological Charge Density Waves at Half-Integer
Filling of a Moiré Superlattice.” Nature Physics, Springer Nature, 2021,
doi:10.1038/s41567-021-01418-6.
short: H. Polshyn, Y. Zhang, M.A. Kumar, T. Soejima, P. Ledwith, K. Watanabe, T.
Taniguchi, A. Vishwanath, M.P. Zaletel, A.F. Young, Nature Physics (2021).
date_created: 2022-01-13T12:30:47Z
date_published: 2021-12-09T00:00:00Z
date_updated: 2022-01-13T14:11:31Z
day: '09'
doi: 10.1038/s41567-021-01418-6
extern: '1'
external_id:
arxiv:
- '2104.01178'
keyword:
- general physics
- astronomy
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2104.01178
month: '12'
oa: 1
oa_version: Preprint
publication: Nature Physics
publication_identifier:
eissn:
- 1745-2481
issn:
- 1745-2473
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Topological charge density waves at half-integer filling of a moiré superlattice
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2021'
...
---
_id: '10649'
abstract:
- lang: eng
text: Harnessing the properties of vortices in superconductors is crucial for fundamental
science and technological applications; thus, it has been an ongoing goal to locally
probe and control vortices. Here, we use a scanning probe technique that enables
studies of vortex dynamics in superconducting systems by leveraging the resonant
behavior of a raster-scanned, magnetic-tipped cantilever. This experimental setup
allows us to image and control vortices, as well as extract key energy scales
of the vortex interactions. Applying this technique to lattices of superconductor
island arrays on a metal, we obtain a variety of striking spatial patterns that
encode information about the energy landscape for vortices in the system. We interpret
these patterns in terms of local vortex dynamics and extract the relative strengths
of the characteristic energy scales in the system, such as the vortex-magnetic
field and vortex-vortex interaction strengths, as well as the vortex chemical
potential. We also demonstrate that the relative strengths of the interactions
can be tuned and show how these interactions shift with an applied bias. The high
degree of tunability and local nature of such vortex imaging and control not only
enable new understanding of vortex interactions, but also have potential applications
in more complex systems such as those relevant to quantum computing.
acknowledgement: This work was supported by the Department of Energy (DOE) Basic Energy
Sciences under Grant No. DE-SC0012649 and the National Science Foundation (NSF)
under Grant No. DMR 17-10437. V.C. was supported by the Gordon and Betty Moore Foundation
EPiQS Initiative through Grant No. GBMF4305. N.M. also acknowledges support from
DOE-EFRC under Grant No. DE-SC0021238 for analysis/manuscript preparation. This
research was carried out in part in the Materials Research Laboratory Central Research
Facilities, University of Illinois.
article_number: '224526'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Tyler R.
full_name: Naibert, Tyler R.
last_name: Naibert
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Rita
full_name: Garrido-Menacho, Rita
last_name: Garrido-Menacho
- first_name: Malcolm
full_name: Durkin, Malcolm
last_name: Durkin
- first_name: Brian
full_name: Wolin, Brian
last_name: Wolin
- first_name: Victor
full_name: Chua, Victor
last_name: Chua
- first_name: Ian
full_name: Mondragon-Shem, Ian
last_name: Mondragon-Shem
- first_name: Taylor
full_name: Hughes, Taylor
last_name: Hughes
- first_name: Nadya
full_name: Mason, Nadya
last_name: Mason
- first_name: Raffi
full_name: Budakian, Raffi
last_name: Budakian
citation:
ama: Naibert TR, Polshyn H, Garrido-Menacho R, et al. Imaging and controlling vortex
dynamics in mesoscopic superconductor-normal-metal-superconductor arrays. Physical
Review B. 2021;103(22). doi:10.1103/physrevb.103.224526
apa: Naibert, T. R., Polshyn, H., Garrido-Menacho, R., Durkin, M., Wolin, B., Chua,
V., … Budakian, R. (2021). Imaging and controlling vortex dynamics in mesoscopic
superconductor-normal-metal-superconductor arrays. Physical Review B. American
Physical Society. https://doi.org/10.1103/physrevb.103.224526
chicago: Naibert, Tyler R., Hryhoriy Polshyn, Rita Garrido-Menacho, Malcolm Durkin,
Brian Wolin, Victor Chua, Ian Mondragon-Shem, Taylor Hughes, Nadya Mason, and
Raffi Budakian. “Imaging and Controlling Vortex Dynamics in Mesoscopic Superconductor-Normal-Metal-Superconductor
Arrays.” Physical Review B. American Physical Society, 2021. https://doi.org/10.1103/physrevb.103.224526.
ieee: T. R. Naibert et al., “Imaging and controlling vortex dynamics in mesoscopic
superconductor-normal-metal-superconductor arrays,” Physical Review B,
vol. 103, no. 22. American Physical Society, 2021.
ista: Naibert TR, Polshyn H, Garrido-Menacho R, Durkin M, Wolin B, Chua V, Mondragon-Shem
I, Hughes T, Mason N, Budakian R. 2021. Imaging and controlling vortex dynamics
in mesoscopic superconductor-normal-metal-superconductor arrays. Physical Review
B. 103(22), 224526.
mla: Naibert, Tyler R., et al. “Imaging and Controlling Vortex Dynamics in Mesoscopic
Superconductor-Normal-Metal-Superconductor Arrays.” Physical Review B,
vol. 103, no. 22, 224526, American Physical Society, 2021, doi:10.1103/physrevb.103.224526.
short: T.R. Naibert, H. Polshyn, R. Garrido-Menacho, M. Durkin, B. Wolin, V. Chua,
I. Mondragon-Shem, T. Hughes, N. Mason, R. Budakian, Physical Review B 103 (2021).
date_created: 2022-01-20T09:39:40Z
date_published: 2021-06-24T00:00:00Z
date_updated: 2022-01-24T08:25:18Z
day: '24'
doi: 10.1103/physrevb.103.224526
extern: '1'
external_id:
arxiv:
- '1705.08956'
intvolume: ' 103'
issue: '22'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1705.08956
month: '06'
oa: 1
oa_version: Preprint
publication: Physical Review B
publication_identifier:
eissn:
- 2469-9969
issn:
- 2469-9950
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Imaging and controlling vortex dynamics in mesoscopic superconductor-normal-metal-superconductor
arrays
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 103
year: '2021'
...
---
_id: '10651'
abstract:
- lang: eng
text: Electrons in the moiré flat bands of magic angle twisted bilayer graphene
aligned to hexagonal boron nitride can break time reversal symmetry and open an
interaction-driven, topological gap. The resulting magnetic order and associated
quantized anomalous Hall effect have properties that diverge substantially from
quantized anomalous Hall effects observed in other systems. I will present transport
data and scanning probe magnetometry data acquired using a nanoSQUID-on-tip microscope.
A quantitative analysis of the magnitude of the magnetization of the Chern magnet
shows that the magnetic moment per moiré unit cell substantially exceeds 1 μB
and grows rapidly in the topological gap, consistent with an orbital origin for
the magnetic order. We find that the Barkhausen jumps observed in transport measurements
can be mapped directly to microscopic motion of ferromagnetic domain walls. These
domain walls are strongly pinned to disorder in the device and are reproducible
across thermal cycles, suggesting coupling between the magnetic degrees of freedom
and structural inhomogeneity.
acknowledgement: I acknowledge and appreciate support from the Hertz Foundation and
from the National Science Foundation Graduate Research Fellowship Program under
grant 1650114.
alternative_title:
- Bulletin of the American Physical Society
article_number: L42.00012
article_processing_charge: No
author:
- first_name: Charles
full_name: Tschirhart, Charles
last_name: Tschirhart
- first_name: Marec
full_name: Serlin, Marec
last_name: Serlin
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Avi G.
full_name: Shragai, Avi G.
last_name: Shragai
- first_name: Zhengchao
full_name: Xia, Zhengchao
last_name: Xia
- first_name: Jiacheng
full_name: Zhu, Jiacheng
last_name: Zhu
- first_name: Yuxuan
full_name: Zhang, Yuxuan
last_name: Zhang
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: Takashi
full_name: Taniguchi, Takashi
last_name: Taniguchi
- first_name: Martin E.
full_name: Huber, Martin E.
last_name: Huber
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
citation:
ama: 'Tschirhart C, Serlin M, Polshyn H, et al. Probing orbital Chern ferromagnet
phase in twisted bilayer graphene. In: APS March Meeting 2021. Vol 66.
American Physical Society; 2021.'
apa: 'Tschirhart, C., Serlin, M., Polshyn, H., Shragai, A. G., Xia, Z., Zhu, J.,
… Young, A. (2021). Probing orbital Chern ferromagnet phase in twisted bilayer
graphene. In APS March Meeting 2021 (Vol. 66). Virtual, United States:
American Physical Society.'
chicago: Tschirhart, Charles, Marec Serlin, Hryhoriy Polshyn, Avi G. Shragai, Zhengchao
Xia, Jiacheng Zhu, Yuxuan Zhang, et al. “Probing Orbital Chern Ferromagnet Phase
in Twisted Bilayer Graphene.” In APS March Meeting 2021, Vol. 66. American
Physical Society, 2021.
ieee: C. Tschirhart et al., “Probing orbital Chern ferromagnet phase in twisted
bilayer graphene,” in APS March Meeting 2021, Virtual, United States, 2021,
vol. 66, no. 1.
ista: 'Tschirhart C, Serlin M, Polshyn H, Shragai AG, Xia Z, Zhu J, Zhang Y, Watanabe
K, Taniguchi T, Huber ME, Young A. 2021. Probing orbital Chern ferromagnet phase
in twisted bilayer graphene. APS March Meeting 2021. APS: American Physical Society,
Bulletin of the American Physical Society, vol. 66, L42.00012.'
mla: Tschirhart, Charles, et al. “Probing Orbital Chern Ferromagnet Phase in Twisted
Bilayer Graphene.” APS March Meeting 2021, vol. 66, no. 1, L42.00012, American
Physical Society, 2021.
short: C. Tschirhart, M. Serlin, H. Polshyn, A.G. Shragai, Z. Xia, J. Zhu, Y. Zhang,
K. Watanabe, T. Taniguchi, M.E. Huber, A. Young, in:, APS March Meeting 2021,
American Physical Society, 2021.
conference:
end_date: 2021-03-19
location: Virtual, United States
name: 'APS: American Physical Society'
start_date: 2021-03-15
date_created: 2022-01-20T15:43:16Z
date_published: 2021-03-01T00:00:00Z
date_updated: 2022-01-27T09:37:51Z
day: '01'
extern: '1'
intvolume: ' 66'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR21/Session/L42.12
month: '03'
oa: 1
oa_version: None
publication: APS March Meeting 2021
publication_identifier:
issn:
- 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Probing orbital Chern ferromagnet phase in twisted bilayer graphene
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 66
year: '2021'
...
---
_id: '10693'
abstract:
- lang: eng
text: High quality graphene heterostructures host an array of fractional quantum
Hall isospin ferromagnets with diverse spin and valley orders. While a variety
of phase transitions have been observed, disentangling the isospin phase diagram
of these states is hampered by the absence of direct probes of spin and valley
order. I will describe nonlocal transport measurements based on launching spin
waves from a gate defined lateral heterojunction, performed in ultra-clean Corbino
geometry graphene devices. At high magnetic fields, we find that the spin-wave
transport signal is detected in all FQH states between ν = 0 and 1; however, between
ν = 1 and 2 only odd numerator FQH states show finite nonlocal transport, despite
the identical ground state spin polarizations in odd- and even numerator states.
The results reveal that the neutral spin-waves are both spin and sublattice polarized
making them a sensitive probe of ground state sublattice structure. Armed with
this understanding, we use nonlocal transport signal to a magnetic field tuned
isospin phase transition, showing that the emergent even denominator state at
ν = 1/2 in monolayer graphene is indeed a multicomponent state featuring equal
populations on each sublattice.
alternative_title:
- Bulletin of the American Physical Society
article_number: B54. 00007
article_processing_charge: No
author:
- first_name: Haoxin
full_name: Zhou, Haoxin
last_name: Zhou
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Takashi
full_name: Tanaguchi, Takashi
last_name: Tanaguchi
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
citation:
ama: 'Zhou H, Polshyn H, Tanaguchi T, Watanabe K, Young A. Sublattice resolved spin
wave transport through graphene fractional quantum Hall states as a probe of isospin
order. In: APS March Meeting 2020. Vol 65. American Physical Society; 2020.'
apa: 'Zhou, H., Polshyn, H., Tanaguchi, T., Watanabe, K., & Young, A. (2020).
Sublattice resolved spin wave transport through graphene fractional quantum Hall
states as a probe of isospin order. In APS March Meeting 2020 (Vol. 65).
Denver, CO, United States: American Physical Society.'
chicago: Zhou, Haoxin, Hryhoriy Polshyn, Takashi Tanaguchi, Kenji Watanabe, and
Andrea Young. “Sublattice Resolved Spin Wave Transport through Graphene Fractional
Quantum Hall States as a Probe of Isospin Order.” In APS March Meeting 2020,
Vol. 65. American Physical Society, 2020.
ieee: H. Zhou, H. Polshyn, T. Tanaguchi, K. Watanabe, and A. Young, “Sublattice
resolved spin wave transport through graphene fractional quantum Hall states as
a probe of isospin order,” in APS March Meeting 2020, Denver, CO, United
States, 2020, vol. 65, no. 1.
ista: 'Zhou H, Polshyn H, Tanaguchi T, Watanabe K, Young A. 2020. Sublattice resolved
spin wave transport through graphene fractional quantum Hall states as a probe
of isospin order. APS March Meeting 2020. APS: American Physical Society, Bulletin
of the American Physical Society, vol. 65, B54. 00007.'
mla: Zhou, Haoxin, et al. “Sublattice Resolved Spin Wave Transport through Graphene
Fractional Quantum Hall States as a Probe of Isospin Order.” APS March Meeting
2020, vol. 65, no. 1, B54. 00007, American Physical Society, 2020.
short: H. Zhou, H. Polshyn, T. Tanaguchi, K. Watanabe, A. Young, in:, APS March
Meeting 2020, American Physical Society, 2020.
conference:
end_date: 2020-03-06
location: Denver, CO, United States
name: 'APS: American Physical Society'
start_date: 2020-03-02
date_created: 2022-01-27T10:50:10Z
date_published: 2020-03-01T00:00:00Z
date_updated: 2022-01-27T10:58:38Z
day: '01'
extern: '1'
intvolume: ' 65'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR20/Session/B54.7
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2020
publication_identifier:
issn:
- 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Sublattice resolved spin wave transport through graphene fractional quantum
Hall states as a probe of isospin order
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 65
year: '2020'
...
---
_id: '10696'
abstract:
- lang: eng
text: We experimentally investigate twisted van der Waals heterostructures of monolayer
graphene rotated with respect to a bernal stacked graphene bilayer. We report
transport measurements for devices with twist angles between 0.9 and 1.4°. The
electric field allows efficient tuning of the width, isolation and the topology
of the moiré bands in this system. By comparing magnetoresistance measurements
to numerical simulations, we develop an understanding of the band structure. Finally,
we observe correlated states at half- and quarter-fillings, which arise when narrow
moire sublattice band is isolated by energy gaps from dispersive bands. We investigate
the effects of in-plane and out-of-plane magnetic field on these states and discuss
the implication for their spin- and valley- polarization.
alternative_title:
- Bulletin of the American Physical Society
article_number: B51.00005
article_processing_charge: No
author:
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Jihang
full_name: Zhu, Jihang
last_name: Zhu
- first_name: Manish
full_name: Kumar, Manish
last_name: Kumar
- first_name: Takashi
full_name: Taniguchi, Takashi
last_name: Taniguchi
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: Allan
full_name: MacDonald, Allan
last_name: MacDonald
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
citation:
ama: 'Polshyn H, Zhu J, Kumar M, et al. Correlated states and tunable topological
bands in twisted monolayer-bilayer graphene heterostructures. In: APS March
Meeting 2020. Vol 65. American Physical Society; 2020.'
apa: 'Polshyn, H., Zhu, J., Kumar, M., Taniguchi, T., Watanabe, K., MacDonald, A.,
& Young, A. (2020). Correlated states and tunable topological bands in twisted
monolayer-bilayer graphene heterostructures. In APS March Meeting 2020
(Vol. 65). Denver, CO, United States: American Physical Society.'
chicago: Polshyn, Hryhoriy, Jihang Zhu, Manish Kumar, Takashi Taniguchi, Kenji Watanabe,
Allan MacDonald, and Andrea Young. “Correlated States and Tunable Topological
Bands in Twisted Monolayer-Bilayer Graphene Heterostructures.” In APS March
Meeting 2020, Vol. 65. American Physical Society, 2020.
ieee: H. Polshyn et al., “Correlated states and tunable topological bands
in twisted monolayer-bilayer graphene heterostructures,” in APS March Meeting
2020, Denver, CO, United States, 2020, vol. 65, no. 1.
ista: 'Polshyn H, Zhu J, Kumar M, Taniguchi T, Watanabe K, MacDonald A, Young A.
2020. Correlated states and tunable topological bands in twisted monolayer-bilayer
graphene heterostructures. APS March Meeting 2020. APS: American Physical Society,
Bulletin of the American Physical Society, vol. 65, B51.00005.'
mla: Polshyn, Hryhoriy, et al. “Correlated States and Tunable Topological Bands
in Twisted Monolayer-Bilayer Graphene Heterostructures.” APS March Meeting
2020, vol. 65, no. 1, B51.00005, American Physical Society, 2020.
short: H. Polshyn, J. Zhu, M. Kumar, T. Taniguchi, K. Watanabe, A. MacDonald, A.
Young, in:, APS March Meeting 2020, American Physical Society, 2020.
conference:
end_date: 2020-03-06
location: Denver, CO, United States
name: 'APS: American Physical Society'
start_date: 2020-03-02
date_created: 2022-01-28T10:09:19Z
date_published: 2020-03-01T00:00:00Z
date_updated: 2022-02-08T10:22:08Z
day: '01'
extern: '1'
intvolume: ' 65'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR20/Session/B51.5
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2020
publication_identifier:
issn:
- 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Correlated states and tunable topological bands in twisted monolayer-bilayer
graphene heterostructures
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 65
year: '2020'
...
---
_id: '10697'
abstract:
- lang: eng
text: We report the observation of a quantized anomalous Hall effect in a moiré
heterostructure consisting of twisted bilayer graphene aligned to an encapsulating
hBN substrate. The effect occurs at a density of 3 electrons per superlattice
unit cell, where we observe magnetic hysteresis and a Hall resistance quantized
to within 0.1% of the resistance quantum at temperatures as high as 3K. In this
first of 3 talks, I will describe the fabrication procedure for our device as
well as basic transport characterization measurements. I will introduce the phenomenology
of twisted bilayer graphene and present evidence for hBN alignment as manifested
in the hierarchy of symmetry-breaking gaps and anomalous magnetoresistance.
acknowledgement: I would like to thank the MURI program, Sloan foundation, AFOSR,
and ARO for their generous support of this work.
alternative_title:
- Bulletin of the American Physical Society
article_number: B59.00012
article_processing_charge: No
arxiv: 1
author:
- first_name: Yuxuan
full_name: Zhang, Yuxuan
last_name: Zhang
- first_name: Marec
full_name: Serlin, Marec
last_name: Serlin
- first_name: Charles
full_name: Tschirhart, Charles
last_name: Tschirhart
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Jiacheng
full_name: Zhu, Jiacheng
last_name: Zhu
- first_name: Leon
full_name: Balents, Leon
last_name: Balents
- first_name: Martin E.
full_name: Huber, Martin E.
last_name: Huber
- first_name: Takashi
full_name: Taniguchi, Takashi
last_name: Taniguchi
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
citation:
ama: 'Zhang Y, Serlin M, Tschirhart C, et al. Intrinsic quantized anomalous Hall
effect in a moiré heterostructure, part I: Device fabrication and transport. In:
APS March Meeting 2020. Vol 65. American Physical Society; 2020.'
apa: 'Zhang, Y., Serlin, M., Tschirhart, C., Polshyn, H., Zhu, J., Balents, L.,
… Young, A. (2020). Intrinsic quantized anomalous Hall effect in a moiré heterostructure,
part I: Device fabrication and transport. In APS March Meeting 2020 (Vol.
65). Denver, CO, United States: American Physical Society.'
chicago: 'Zhang, Yuxuan, Marec Serlin, Charles Tschirhart, Hryhoriy Polshyn, Jiacheng
Zhu, Leon Balents, Martin E. Huber, Takashi Taniguchi, Kenji Watanabe, and Andrea
Young. “Intrinsic Quantized Anomalous Hall Effect in a Moiré Heterostructure,
Part I: Device Fabrication and Transport.” In APS March Meeting 2020, Vol.
65. American Physical Society, 2020.'
ieee: 'Y. Zhang et al., “Intrinsic quantized anomalous Hall effect in a moiré
heterostructure, part I: Device fabrication and transport,” in APS March Meeting
2020, Denver, CO, United States, 2020, vol. 65, no. 1.'
ista: 'Zhang Y, Serlin M, Tschirhart C, Polshyn H, Zhu J, Balents L, Huber ME, Taniguchi
T, Watanabe K, Young A. 2020. Intrinsic quantized anomalous Hall effect in a moiré
heterostructure, part I: Device fabrication and transport. APS March Meeting 2020.
APS: American Physical Society, Bulletin of the American Physical Society, vol.
65, B59.00012.'
mla: 'Zhang, Yuxuan, et al. “Intrinsic Quantized Anomalous Hall Effect in a Moiré
Heterostructure, Part I: Device Fabrication and Transport.” APS March Meeting
2020, vol. 65, no. 1, B59.00012, American Physical Society, 2020.'
short: Y. Zhang, M. Serlin, C. Tschirhart, H. Polshyn, J. Zhu, L. Balents, M.E.
Huber, T. Taniguchi, K. Watanabe, A. Young, in:, APS March Meeting 2020, American
Physical Society, 2020.
conference:
end_date: 2020-03-06
location: Denver, CO, United States
name: 'APS: American Physical Society'
start_date: 2020-03-02
date_created: 2022-01-28T10:28:35Z
date_published: 2020-03-01T00:00:00Z
date_updated: 2023-02-21T15:57:52Z
day: '01'
extern: '1'
external_id:
arxiv:
- '1907.00261'
intvolume: ' 65'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR20/Session/B59.12
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2020
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
related_material:
record:
- id: '10619'
relation: other
status: public
status: public
title: 'Intrinsic quantized anomalous Hall effect in a moiré heterostructure, part
I: Device fabrication and transport'
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 65
year: '2020'
...
---
_id: '10698'
abstract:
- lang: eng
text: This is the second of three talks describing the observation and characterization
of a ferromagnetic moiré heterostructure based on twisted bilayer graphene aligned
to hexagonal boron nitride. I will compare the qualitative and quantitative features
of this observed quantum anomalous Hall state to traditional systems engineered
from thin film (Bi,Sb)2Te3 topological insulators. In particular, we find that
the measured electronic energy gap of ~30K is several times higher than the Curie
temperature, consistent with a lack of disorder associated with magnetic dopants.
In this system, the quantization arises from spontaneous ferromagnetic polarization
into a single spin and valley moiré subband, which is topological despite the
lack of spin orbit coupling. I will also discuss the observation of current induced
switching, which allows the magnetic state of the heterostructure to be controllably
reversed with currents as small as a few nanoamperes.
acknowledgement: I would like to thank the MURI Program, AFOSR, Sloan Foundation,
and the ARO for their generous support of this work.
alternative_title:
- Bulletin of the American Physical Society
article_number: B59.00011
article_processing_charge: No
arxiv: 1
author:
- first_name: Marec
full_name: Serlin, Marec
last_name: Serlin
- first_name: Charles
full_name: Tschirhart, Charles
last_name: Tschirhart
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Yuxuan
full_name: Zhang, Yuxuan
last_name: Zhang
- first_name: Jiacheng
full_name: Zhu, Jiacheng
last_name: Zhu
- first_name: Martin E.
full_name: Huber, Martin E.
last_name: Huber
- first_name: Leon
full_name: Balents, Leon
last_name: Balents
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: Takashi
full_name: Tanaguchi, Takashi
last_name: Tanaguchi
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
citation:
ama: 'Serlin M, Tschirhart C, Polshyn H, et al. Intrinsic quantized anomalous Hall
effect in a moiré heterostructure, part II: Temperature dependence and current
switching. In: APS March Meeting 2020. Vol 65. American Physical Society;
2020.'
apa: 'Serlin, M., Tschirhart, C., Polshyn, H., Zhang, Y., Zhu, J., Huber, M. E.,
… Young, A. (2020). Intrinsic quantized anomalous Hall effect in a moiré heterostructure,
part II: Temperature dependence and current switching. In APS March Meeting
2020 (Vol. 65). Denver, CO, United States: American Physical Society.'
chicago: 'Serlin, Marec, Charles Tschirhart, Hryhoriy Polshyn, Yuxuan Zhang, Jiacheng
Zhu, Martin E. Huber, Leon Balents, Kenji Watanabe, Takashi Tanaguchi, and Andrea
Young. “Intrinsic Quantized Anomalous Hall Effect in a Moiré Heterostructure,
Part II: Temperature Dependence and Current Switching.” In APS March Meeting
2020, Vol. 65. American Physical Society, 2020.'
ieee: 'M. Serlin et al., “Intrinsic quantized anomalous Hall effect in a
moiré heterostructure, part II: Temperature dependence and current switching,”
in APS March Meeting 2020, Denver, CO, United States, 2020, vol. 65, no.
1.'
ista: 'Serlin M, Tschirhart C, Polshyn H, Zhang Y, Zhu J, Huber ME, Balents L, Watanabe
K, Tanaguchi T, Young A. 2020. Intrinsic quantized anomalous Hall effect in a
moiré heterostructure, part II: Temperature dependence and current switching.
APS March Meeting 2020. APS: American Physical Society, Bulletin of the American
Physical Society, vol. 65, B59.00011.'
mla: 'Serlin, Marec, et al. “Intrinsic Quantized Anomalous Hall Effect in a Moiré
Heterostructure, Part II: Temperature Dependence and Current Switching.” APS
March Meeting 2020, vol. 65, no. 1, B59.00011, American Physical Society,
2020.'
short: M. Serlin, C. Tschirhart, H. Polshyn, Y. Zhang, J. Zhu, M.E. Huber, L. Balents,
K. Watanabe, T. Tanaguchi, A. Young, in:, APS March Meeting 2020, American Physical
Society, 2020.
conference:
end_date: 2020-03-06
location: Denver, CO, United States
name: 'APS: American Physical Society'
start_date: 2020-03-02
date_created: 2022-01-28T10:46:57Z
date_published: 2020-03-01T00:00:00Z
date_updated: 2023-02-21T15:57:52Z
day: '01'
extern: '1'
external_id:
arxiv:
- '1907.00261'
intvolume: ' 65'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR20/Session/B59.11
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2020
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
related_material:
record:
- id: '10619'
relation: other
status: public
status: public
title: 'Intrinsic quantized anomalous Hall effect in a moiré heterostructure, part
II: Temperature dependence and current switching'
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 65
year: '2020'
...
---
_id: '10699'
abstract:
- lang: eng
text: This is the third of three talks describing the observation and characterization
of a ferromagnetic moiré heterostructure based on twisted bilayer graphene aligned
to hexagonal boron nitride. In this segment I will present scanning probe magnetometry
data acquired using a nanoSQUID-on-tip microscope, which provides ~150 nm spatial
resolution and a field sensitivity of ~10 nT/rtHz. We study the distribution of
magnetic domains within the device as a function of density, magnetic field training,
and DC current. Our data allow us to constrain the magnitude of the orbital magnetic
moment of the electrons in the QAH state. Comparison with simultaneously acquired
transport data allows us to precisely correlate single domain dynamics with discrete
jumps in the observed anomalous Hall signal.
acknowledgement: I would like to thank the MURI program, Sloan foundation, AFOSR,
and ARO for their generous support of this work. I would also like to thank the
NSF GRFP and the Hertz foundation for their generous support of my graduate studies.
alternative_title:
- Bulletin of the American Physical Society
article_number: B59.00013
article_processing_charge: No
arxiv: 1
author:
- first_name: Charles
full_name: Tschirhart, Charles
last_name: Tschirhart
- first_name: Marec
full_name: Serlin, Marec
last_name: Serlin
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Yuxuan
full_name: Zhang, Yuxuan
last_name: Zhang
- first_name: Jiacheng
full_name: Zhu, Jiacheng
last_name: Zhu
- first_name: Leon
full_name: Balents, Leon
last_name: Balents
- first_name: Martin E.
full_name: Huber, Martin E.
last_name: Huber
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: Takashi
full_name: Tanaguchi, Takashi
last_name: Tanaguchi
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
citation:
ama: 'Tschirhart C, Serlin M, Polshyn H, et al. Intrinsic quantized anomalous Hall
effect in a moiré heterostructure, part III: Scanning probe magnetometry. In:
APS March Meeting 2020. Vol 65. American Physical Society; 2020.'
apa: 'Tschirhart, C., Serlin, M., Polshyn, H., Zhang, Y., Zhu, J., Balents, L.,
… Young, A. (2020). Intrinsic quantized anomalous Hall effect in a moiré heterostructure,
part III: Scanning probe magnetometry. In APS March Meeting 2020 (Vol.
65). Denver, CO, United States: American Physical Society.'
chicago: 'Tschirhart, Charles, Marec Serlin, Hryhoriy Polshyn, Yuxuan Zhang, Jiacheng
Zhu, Leon Balents, Martin E. Huber, Kenji Watanabe, Takashi Tanaguchi, and Andrea
Young. “Intrinsic Quantized Anomalous Hall Effect in a Moiré Heterostructure,
Part III: Scanning Probe Magnetometry.” In APS March Meeting 2020, Vol.
65. American Physical Society, 2020.'
ieee: 'C. Tschirhart et al., “Intrinsic quantized anomalous Hall effect in
a moiré heterostructure, part III: Scanning probe magnetometry,” in APS March
Meeting 2020, Denver, CO, United States, 2020, vol. 65, no. 1.'
ista: 'Tschirhart C, Serlin M, Polshyn H, Zhang Y, Zhu J, Balents L, Huber ME, Watanabe
K, Tanaguchi T, Young A. 2020. Intrinsic quantized anomalous Hall effect in a
moiré heterostructure, part III: Scanning probe magnetometry. APS March Meeting
2020. APS: American Physical Society, Bulletin of the American Physical Society,
vol. 65, B59.00013.'
mla: 'Tschirhart, Charles, et al. “Intrinsic Quantized Anomalous Hall Effect in
a Moiré Heterostructure, Part III: Scanning Probe Magnetometry.” APS March
Meeting 2020, vol. 65, no. 1, B59.00013, American Physical Society, 2020.'
short: C. Tschirhart, M. Serlin, H. Polshyn, Y. Zhang, J. Zhu, L. Balents, M.E.
Huber, K. Watanabe, T. Tanaguchi, A. Young, in:, APS March Meeting 2020, American
Physical Society, 2020.
conference:
end_date: 2020-03-06
location: Denver, CO, United States
name: 'APS: American Physical Society'
start_date: 2020-03-02
date_created: 2022-01-28T10:57:49Z
date_published: 2020-03-01T00:00:00Z
date_updated: 2023-02-21T15:57:52Z
day: '01'
extern: '1'
external_id:
arxiv:
- '1907.00261'
intvolume: ' 65'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR20/Session/B59.13
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2020
publication_identifier:
issn:
- 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
related_material:
record:
- id: '10619'
relation: other
status: public
status: public
title: 'Intrinsic quantized anomalous Hall effect in a moiré heterostructure, part
III: Scanning probe magnetometry'
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 65
year: '2020'
...
---
_id: '10701'
abstract:
- lang: eng
text: Partially filled Landau levels host competing electronic orders. For example,
electron solids may prevail close to integer filling of the Landau levels before
giving way to fractional quantum Hall liquids at higher carrier density1,2. Here,
we report the observation of an electron solid with non-collinear spin texture
in monolayer graphene, consistent with solidification of skyrmions3—topological
spin textures characterized by quantized electrical charge4,5. We probe the spin
texture of the solids using a modified Corbino geometry that allows ferromagnetic
magnons to be launched and detected6,7. We find that magnon transport is highly
efficient when one Landau level is filled (ν=1), consistent with quantum Hall
ferromagnetic spin polarization. However, even minimal doping immediately quenches
the magnon signal while leaving the vanishing low-temperature charge conductivity
unchanged. Our results can be understood by the formation of a solid of charged
skyrmions near ν=1, whose non-collinear spin texture leads to rapid magnon decay.
Data near fractional fillings show evidence of several fractional skyrmion solids,
suggesting that graphene hosts a highly tunable landscape of coupled spin and
charge orders.
acknowledgement: We acknowledge discussions with B. Halperin, C. Huang, A. Macdonald
and M. Zalatel. Experimental work at UCSB was supported by the Army Research Office
under awards nos. MURI W911NF-16-1-0361 and W911NF-16-1-0482. K.W. and T.T. acknowledge
support from the Elemental Strategy Initiative conducted by MEXT (Japan) and CREST
(JPMJCR15F3), JST. A.F.Y. acknowledges the support of the David and Lucile Packard
Foundation and and Alfred. P. Sloan Foundation.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Haoxin
full_name: Zhou, Haoxin
last_name: Zhou
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Takashi
full_name: Taniguchi, Takashi
last_name: Taniguchi
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: Andrea F.
full_name: Young, Andrea F.
last_name: Young
citation:
ama: Zhou H, Polshyn H, Taniguchi T, Watanabe K, Young AF. Skyrmion solids in monolayer
graphene. Nature Physics. 2020;16(2):154-158. doi:10.1038/s41567-019-0729-8
apa: Zhou, H., Polshyn, H., Taniguchi, T., Watanabe, K., & Young, A. F. (2020).
Skyrmion solids in monolayer graphene. Nature Physics. Springer Nature.
https://doi.org/10.1038/s41567-019-0729-8
chicago: Zhou, Haoxin, Hryhoriy Polshyn, Takashi Taniguchi, Kenji Watanabe, and
Andrea F. Young. “Skyrmion Solids in Monolayer Graphene.” Nature Physics.
Springer Nature, 2020. https://doi.org/10.1038/s41567-019-0729-8.
ieee: H. Zhou, H. Polshyn, T. Taniguchi, K. Watanabe, and A. F. Young, “Skyrmion
solids in monolayer graphene,” Nature Physics, vol. 16, no. 2. Springer
Nature, pp. 154–158, 2020.
ista: Zhou H, Polshyn H, Taniguchi T, Watanabe K, Young AF. 2020. Skyrmion solids
in monolayer graphene. Nature Physics. 16(2), 154–158.
mla: Zhou, Haoxin, et al. “Skyrmion Solids in Monolayer Graphene.” Nature Physics,
vol. 16, no. 2, Springer Nature, 2020, pp. 154–58, doi:10.1038/s41567-019-0729-8.
short: H. Zhou, H. Polshyn, T. Taniguchi, K. Watanabe, A.F. Young, Nature Physics
16 (2020) 154–158.
date_created: 2022-01-28T12:04:09Z
date_published: 2020-02-01T00:00:00Z
date_updated: 2022-01-31T07:10:07Z
day: '01'
doi: 10.1038/s41567-019-0729-8
extern: '1'
external_id:
arxiv:
- '1904.11485'
intvolume: ' 16'
issue: '2'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1904.11485
month: '02'
oa: 1
oa_version: Preprint
page: 154-158
publication: Nature Physics
publication_identifier:
eissn:
- 1745-2481
issn:
- 1745-2473
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
status: public
title: Skyrmion solids in monolayer graphene
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 16
year: '2020'
...
---
_id: '10618'
abstract:
- lang: eng
text: Magnetism typically arises from the joint effect of Fermi statistics and repulsive
Coulomb interactions, which favours ground states with non-zero electron spin.
As a result, controlling spin magnetism with electric fields—a longstanding technological
goal in spintronics and multiferroics1,2—can be achieved only indirectly. Here
we experimentally demonstrate direct electric-field control of magnetic states
in an orbital Chern insulator3,4,5,6, a magnetic system in which non-trivial band
topology favours long-range order of orbital angular momentum but the spins are
thought to remain disordered7,8,9,10,11,12,13,14. We use van der Waals heterostructures
consisting of a graphene monolayer rotationally faulted with respect to a Bernal-stacked
bilayer to realize narrow and topologically non-trivial valley-projected moiré
minibands15,16,17. At fillings of one and three electrons per moiré unit cell
within these bands, we observe quantized anomalous Hall effects18 with transverse
resistance approximately equal to h/2e2 (where h is Planck’s constant and e is
the charge on the electron), which is indicative of spontaneous polarization of
the system into a single-valley-projected band with a Chern number equal to two.
At a filling of three electrons per moiré unit cell, we find that the sign of
the quantum anomalous Hall effect can be reversed via field-effect control of
the chemical potential; moreover, this transition is hysteretic, which we use
to demonstrate non-volatile electric-field-induced reversal of the magnetic state.
A theoretical analysis19 indicates that the effect arises from the topological
edge states, which drive a change in sign of the magnetization and thus a reversal
in the favoured magnetic state. Voltage control of magnetic states can be used
to electrically pattern non-volatile magnetic-domain structures hosting chiral
edge states, with applications ranging from reconfigurable microwave circuit elements
to ultralow-power magnetic memories.
acknowledgement: We acknowledge discussions with J. Checkelsky, S. Chen, C. Dean,
M. Yankowitz, D. Reilly, I. Sodemann and M. Zaletel. Work at UCSB was primarily
supported by the ARO under MURI W911NF-16-1-0361. Measurements of twisted bilayer
graphene (Extended Data Fig. 8) and measurements at elevated temperatures (Extended
Data Fig. 3) were supported by a SEED grant and made use of shared facilities of
the UCSB MRSEC (NSF DMR 1720256), a member of the Materials Research Facilities
Network (www.mrfn.org). A.F.Y. acknowledges the support of the David and Lucille
Packard Foundation under award 2016-65145. A.H.M. and J.Z. were supported by the
National Science Foundation through the Center for Dynamics and Control of Materials,
an NSF MRSEC under Cooperative Agreement number DMR-1720595, and by the Welch Foundation
under grant TBF1473. C.L.T. acknowledges support from the Hertz Foundation and from
the National Science Foundation Graduate Research Fellowship Program under grant
1650114. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative
conducted by the MEXT, Japan, Grant Number JPMXP0112101001, JSPS KAKENHI grant numbers
JP20H00354 and the CREST(JPMJCR15F3), JST.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: J.
full_name: Zhu, J.
last_name: Zhu
- first_name: M. A.
full_name: Kumar, M. A.
last_name: Kumar
- first_name: Y.
full_name: Zhang, Y.
last_name: Zhang
- first_name: F.
full_name: Yang, F.
last_name: Yang
- first_name: C. L.
full_name: Tschirhart, C. L.
last_name: Tschirhart
- first_name: M.
full_name: Serlin, M.
last_name: Serlin
- first_name: K.
full_name: Watanabe, K.
last_name: Watanabe
- first_name: T.
full_name: Taniguchi, T.
last_name: Taniguchi
- first_name: A. H.
full_name: MacDonald, A. H.
last_name: MacDonald
- first_name: A. F.
full_name: Young, A. F.
last_name: Young
citation:
ama: Polshyn H, Zhu J, Kumar MA, et al. Electrical switching of magnetic order in
an orbital Chern insulator. Nature. 2020;588(7836):66-70. doi:10.1038/s41586-020-2963-8
apa: Polshyn, H., Zhu, J., Kumar, M. A., Zhang, Y., Yang, F., Tschirhart, C. L.,
… Young, A. F. (2020). Electrical switching of magnetic order in an orbital Chern
insulator. Nature. Springer Nature. https://doi.org/10.1038/s41586-020-2963-8
chicago: Polshyn, Hryhoriy, J. Zhu, M. A. Kumar, Y. Zhang, F. Yang, C. L. Tschirhart,
M. Serlin, et al. “Electrical Switching of Magnetic Order in an Orbital Chern
Insulator.” Nature. Springer Nature, 2020. https://doi.org/10.1038/s41586-020-2963-8.
ieee: H. Polshyn et al., “Electrical switching of magnetic order in an orbital
Chern insulator,” Nature, vol. 588, no. 7836. Springer Nature, pp. 66–70,
2020.
ista: Polshyn H, Zhu J, Kumar MA, Zhang Y, Yang F, Tschirhart CL, Serlin M, Watanabe
K, Taniguchi T, MacDonald AH, Young AF. 2020. Electrical switching of magnetic
order in an orbital Chern insulator. Nature. 588(7836), 66–70.
mla: Polshyn, Hryhoriy, et al. “Electrical Switching of Magnetic Order in an Orbital
Chern Insulator.” Nature, vol. 588, no. 7836, Springer Nature, 2020, pp.
66–70, doi:10.1038/s41586-020-2963-8.
short: H. Polshyn, J. Zhu, M.A. Kumar, Y. Zhang, F. Yang, C.L. Tschirhart, M. Serlin,
K. Watanabe, T. Taniguchi, A.H. MacDonald, A.F. Young, Nature 588 (2020) 66–70.
date_created: 2022-01-13T14:12:17Z
date_published: 2020-11-23T00:00:00Z
date_updated: 2022-01-13T14:21:04Z
day: '23'
doi: 10.1038/s41586-020-2963-8
extern: '1'
external_id:
arxiv:
- '2004.11353'
pmid:
- '33230333'
intvolume: ' 588'
issue: '7836'
keyword:
- multidisciplinary
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2004.11353
month: '11'
oa: 1
oa_version: Preprint
page: 66-70
pmid: 1
publication: Nature
publication_identifier:
eissn:
- 1476-4687
issn:
- 0028-0836
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Electrical switching of magnetic order in an orbital Chern insulator
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 588
year: '2020'
...
---
_id: '10650'
abstract:
- lang: eng
text: The understanding of material systems with strong electron-electron interactions
is the central problem in modern condensed matter physics. Despite this, the essential
physics of many of these materials is still not understood and we have no overall
perspective on their properties. Moreover, we have very little ability to make
predictions in this class of systems. In this manuscript we share our personal
views of what the major open problems are in correlated electron systems and we
discuss some possible routes to make progress in this rich and fascinating field.
This manuscript is the result of the vigorous discussions and deliberations that
took place at Johns Hopkins University during a three-day workshop January 27,
28, and 29, 2020 that brought together six senior scientists and 46 more junior
scientists. Our hope, is that the topics we have presented will provide inspiration
for others working in this field and motivation for the idea that significant
progress can be made on very hard problems if we focus our collective energies.
acknowledgement: "We thank NSF CMP program for suggestions regarding the topic and
general structure of the workshop. This project was supported by the NSF DMR-2002329
and The Gordon and Betty Moore Foundation (GBMF) EPiQS initiative. We would like
to sincerely thank A. Kapitulnik, A. J. Leggett, M.B. Maple, T.M. McQueen, M. Norman,
P. S. Riseborough, and G. A. Sawatzky for their lectures at the workshop and advice
on the writing of this manuscript. We would also like to thank G. Blumberg, C. Broholm,
S. Crooker, N. Drichko, and A. Patel for helpful consultation on topics discussed\r\nherein.
A number of individuals also had independent support: (AA, EH; GBMF-4305), (IMH;
GBMF-9071), (HJC; NHMFL is supported by the NSF DMR-1644779 and the state of Florida),
(YH, AZ; Miller Institute for Basic Research in Science), (YC; US DOE-BES DEAC02-06CH11357),
(AS; Spallation Neutron Source, a DOE Office of Science User Facility operated by
ORNL), (SAAG; ARO-W911NF-18-1-0290, NSF DMR-1455233), (YW; DOE-BES DE-SC0019331,
GBMF-4532)."
article_processing_charge: No
arxiv: 1
author:
- first_name: A
full_name: Alexandradinata, A
last_name: Alexandradinata
- first_name: N.P.
full_name: Armitage, N.P.
last_name: Armitage
- first_name: Andrey
full_name: Baydin, Andrey
last_name: Baydin
- first_name: Wenli
full_name: Bi, Wenli
last_name: Bi
- first_name: Yue
full_name: Cao, Yue
last_name: Cao
- first_name: Hitesh J.
full_name: Changlani, Hitesh J.
last_name: Changlani
- first_name: Eli
full_name: Chertkov, Eli
last_name: Chertkov
- first_name: Eduardo H.
full_name: da Silva Neto, Eduardo H.
last_name: da Silva Neto
- first_name: Luca
full_name: Delacretaz, Luca
last_name: Delacretaz
- first_name: Ismail
full_name: El Baggari, Ismail
last_name: El Baggari
- first_name: G.M.
full_name: Ferguson, G.M.
last_name: Ferguson
- first_name: William J.
full_name: Gannon, William J.
last_name: Gannon
- first_name: Sayed Ali Akbar
full_name: Ghorashi, Sayed Ali Akbar
last_name: Ghorashi
- first_name: Berit H.
full_name: Goodge, Berit H.
last_name: Goodge
- first_name: Olga
full_name: Goulko, Olga
last_name: Goulko
- first_name: G.
full_name: Grissonnache, G.
last_name: Grissonnache
- first_name: Alannah
full_name: Hallas, Alannah
last_name: Hallas
- first_name: Ian M.
full_name: Hayes, Ian M.
last_name: Hayes
- first_name: Yu
full_name: He, Yu
last_name: He
- first_name: Edwin W.
full_name: Huang, Edwin W.
last_name: Huang
- first_name: Anshu
full_name: Kogar, Anshu
last_name: Kogar
- first_name: Divine
full_name: Kumah, Divine
last_name: Kumah
- first_name: Jong Yeon
full_name: Lee, Jong Yeon
last_name: Lee
- first_name: A.
full_name: Legros, A.
last_name: Legros
- first_name: Fahad
full_name: Mahmood, Fahad
last_name: Mahmood
- first_name: Yulia
full_name: Maximenko, Yulia
last_name: Maximenko
- first_name: Nick
full_name: Pellatz, Nick
last_name: Pellatz
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Tarapada
full_name: Sarkar, Tarapada
last_name: Sarkar
- first_name: Allen
full_name: Scheie, Allen
last_name: Scheie
- first_name: Kyle L.
full_name: Seyler, Kyle L.
last_name: Seyler
- first_name: Zhenzhong
full_name: Shi, Zhenzhong
last_name: Shi
- first_name: Brian
full_name: Skinner, Brian
last_name: Skinner
- first_name: Lucia
full_name: Steinke, Lucia
last_name: Steinke
- first_name: K.
full_name: Thirunavukkuarasu, K.
last_name: Thirunavukkuarasu
- first_name: Thaís Victa
full_name: Trevisan, Thaís Victa
last_name: Trevisan
- first_name: Michael
full_name: Vogl, Michael
last_name: Vogl
- first_name: Pavel A.
full_name: Volkov, Pavel A.
last_name: Volkov
- first_name: Yao
full_name: Wang, Yao
last_name: Wang
- first_name: Yishu
full_name: Wang, Yishu
last_name: Wang
- first_name: Di
full_name: Wei, Di
last_name: Wei
- first_name: Kaya
full_name: Wei, Kaya
last_name: Wei
- first_name: Shuolong
full_name: Yang, Shuolong
last_name: Yang
- first_name: Xian
full_name: Zhang, Xian
last_name: Zhang
- first_name: Ya-Hui
full_name: Zhang, Ya-Hui
last_name: Zhang
- first_name: Liuyan
full_name: Zhao, Liuyan
last_name: Zhao
- first_name: Alfred
full_name: Zong, Alfred
last_name: Zong
citation:
ama: Alexandradinata A, Armitage NP, Baydin A, et al. The future of the correlated
electron problem. arXiv.
apa: Alexandradinata, A., Armitage, N. P., Baydin, A., Bi, W., Cao, Y., Changlani,
H. J., … Zong, A. (n.d.). The future of the correlated electron problem. arXiv.
chicago: Alexandradinata, A, N.P. Armitage, Andrey Baydin, Wenli Bi, Yue Cao, Hitesh
J. Changlani, Eli Chertkov, et al. “The Future of the Correlated Electron Problem.”
ArXiv, n.d.
ieee: A. Alexandradinata et al., “The future of the correlated electron problem,”
arXiv. .
ista: Alexandradinata A, Armitage NP, Baydin A, Bi W, Cao Y, Changlani HJ, Chertkov
E, da Silva Neto EH, Delacretaz L, El Baggari I, Ferguson GM, Gannon WJ, Ghorashi
SAA, Goodge BH, Goulko O, Grissonnache G, Hallas A, Hayes IM, He Y, Huang EW,
Kogar A, Kumah D, Lee JY, Legros A, Mahmood F, Maximenko Y, Pellatz N, Polshyn
H, Sarkar T, Scheie A, Seyler KL, Shi Z, Skinner B, Steinke L, Thirunavukkuarasu
K, Trevisan TV, Vogl M, Volkov PA, Wang Y, Wang Y, Wei D, Wei K, Yang S, Zhang
X, Zhang Y-H, Zhao L, Zong A. The future of the correlated electron problem. arXiv,
.
mla: Alexandradinata, A., et al. “The Future of the Correlated Electron Problem.”
ArXiv.
short: A. Alexandradinata, N.P. Armitage, A. Baydin, W. Bi, Y. Cao, H.J. Changlani,
E. Chertkov, E.H. da Silva Neto, L. Delacretaz, I. El Baggari, G.M. Ferguson,
W.J. Gannon, S.A.A. Ghorashi, B.H. Goodge, O. Goulko, G. Grissonnache, A. Hallas,
I.M. Hayes, Y. He, E.W. Huang, A. Kogar, D. Kumah, J.Y. Lee, A. Legros, F. Mahmood,
Y. Maximenko, N. Pellatz, H. Polshyn, T. Sarkar, A. Scheie, K.L. Seyler, Z. Shi,
B. Skinner, L. Steinke, K. Thirunavukkuarasu, T.V. Trevisan, M. Vogl, P.A. Volkov,
Y. Wang, Y. Wang, D. Wei, K. Wei, S. Yang, X. Zhang, Y.-H. Zhang, L. Zhao, A.
Zong, ArXiv (n.d.).
date_created: 2022-01-20T10:55:36Z
date_published: 2020-10-01T00:00:00Z
date_updated: 2022-01-24T08:05:51Z
day: '01'
extern: '1'
external_id:
arxiv:
- '2010.00584'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2010.00584
month: '10'
oa: 1
oa_version: Preprint
page: '55'
publication: arXiv
publication_status: submitted
status: public
title: The future of the correlated electron problem
type: preprint
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2020'
...
---
_id: '10664'
abstract:
- lang: eng
text: "Since the discovery of correlated insulators and superconductivity in magic-angle
twisted bilayer graphene (tBLG) ([1, 2], JCCM April 2018), theorists have been
excitedly pursuing the alluring mix of band topology, symmetry breaking, Mott
insulators and superconductivity at play, as well as the potential relation (if
any) to high-Tc physics. Now a new stream\r\nof experimental work is arriving
which further enriches the story. To briefly recap Episodes 1 and 2 (JCCM April
and November 2018), when two graphene layers are stacked with a small rotational
mismatch θ, the resulting long-wavelength moire pattern leads to a superlattice
potential which reconstructs the low energy band structure. When θ approaches
the “magic-angle” θM ∼ 1 ◦, the band structure features eight nearly-flat bands
which fill when the electron number per moire unit cell, n/n0, lies between −4
< n/n0 < 4. The bands can be counted as 8 = 2 × 2 × 2: for each spin (2×) and
valley (2×) characteristic of monolayergraphene, tBLG has has 2× flat bands which
cross at mini-Dirac points."
article_processing_charge: No
article_type: original
author:
- first_name: Mathew
full_name: Yankowitz, Mathew
last_name: Yankowitz
- first_name: Shaowen
full_name: Chen, Shaowen
last_name: Chen
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: K.
full_name: Watanabe, K.
last_name: Watanabe
- first_name: T.
full_name: Taniguchi, T.
last_name: Taniguchi
- first_name: David
full_name: Graf, David
last_name: Graf
- first_name: Andrea F.
full_name: Young, Andrea F.
last_name: Young
- first_name: Cory R.
full_name: Dean, Cory R.
last_name: Dean
- first_name: Aaron L.
full_name: Sharpe, Aaron L.
last_name: Sharpe
- first_name: E.J.
full_name: Fox, E.J.
last_name: Fox
- first_name: A.W.
full_name: Barnard, A.W.
last_name: Barnard
- first_name: Joe
full_name: Finney, Joe
last_name: Finney
citation:
ama: Yankowitz M, Chen S, Polshyn H, et al. New correlated phenomena in magic-angle
twisted bilayer graphene/s. Journal Club for Condensed Matter Physics.
2019;03. doi:10.36471/jccm_february_2019_03
apa: Yankowitz, M., Chen, S., Polshyn, H., Watanabe, K., Taniguchi, T., Graf, D.,
… Finney, J. (2019). New correlated phenomena in magic-angle twisted bilayer graphene/s.
Journal Club for Condensed Matter Physics. Simons Foundation ; University
of California, Riverside. https://doi.org/10.36471/jccm_february_2019_03
chicago: Yankowitz, Mathew, Shaowen Chen, Hryhoriy Polshyn, K. Watanabe, T. Taniguchi,
David Graf, Andrea F. Young, et al. “New Correlated Phenomena in Magic-Angle Twisted
Bilayer Graphene/S.” Journal Club for Condensed Matter Physics. Simons
Foundation ; University of California, Riverside, 2019. https://doi.org/10.36471/jccm_february_2019_03.
ieee: M. Yankowitz et al., “New correlated phenomena in magic-angle twisted
bilayer graphene/s,” Journal Club for Condensed Matter Physics, vol. 03.
Simons Foundation ; University of California, Riverside, 2019.
ista: Yankowitz M, Chen S, Polshyn H, Watanabe K, Taniguchi T, Graf D, Young AF,
Dean CR, Sharpe AL, Fox EJ, Barnard AW, Finney J. 2019. New correlated phenomena
in magic-angle twisted bilayer graphene/s. Journal Club for Condensed Matter Physics.
03.
mla: Yankowitz, Mathew, et al. “New Correlated Phenomena in Magic-Angle Twisted
Bilayer Graphene/S.” Journal Club for Condensed Matter Physics, vol. 03,
Simons Foundation ; University of California, Riverside, 2019, doi:10.36471/jccm_february_2019_03.
short: M. Yankowitz, S. Chen, H. Polshyn, K. Watanabe, T. Taniguchi, D. Graf, A.F.
Young, C.R. Dean, A.L. Sharpe, E.J. Fox, A.W. Barnard, J. Finney, Journal Club
for Condensed Matter Physics 03 (2019).
date_created: 2022-01-25T15:09:58Z
date_published: 2019-02-28T00:00:00Z
date_updated: 2022-01-25T15:56:39Z
day: '28'
doi: 10.36471/jccm_february_2019_03
intvolume: ' 3'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://www.condmatjclub.org/?p=3541
month: '02'
oa: 1
oa_version: Published Version
publication: Journal Club for Condensed Matter Physics
publication_status: published
publisher: Simons Foundation ; University of California, Riverside
quality_controlled: '1'
status: public
title: New correlated phenomena in magic-angle twisted bilayer graphene/s
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: '03'
year: '2019'
...
---
_id: '10722'
abstract:
- lang: eng
text: Bilayer graphene, rotationally faulted to ~1.1 degree misalignment, has recently
been shown to host superconducting and resistive states associated with the formation
of a flat electronic band. While numerous theories exist for the origins of both
states, direct validation of these theories remains an outstanding experimental
problem. Here, we focus on the resistive states occurring at commensurate filling
(1/2, 1/4, and 3/4) of the two lowest superlattice bands. We test theoretical
proposals that these states arise due to broken spin—and/or valley—symmetry by
performing direct magnetic imaging with nanoscale SQUID-on-tip microscopy. This
technique provides single-spin resolved magnetometry on sub-100nm length scales.
I will present imaging data from our 4.2K nSOT microscope on graphite-gated twisted
bilayers near the flat band condition and discuss the implications for the physics
of the commensurate resistive states.
alternative_title:
- Bulletin of the American Physical Society
article_number: L14.00006
article_processing_charge: No
author:
- first_name: Marec
full_name: Serlin, Marec
last_name: Serlin
- first_name: Charles
full_name: Tschirhart, Charles
last_name: Tschirhart
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Jiacheng
full_name: Zhu, Jiacheng
last_name: Zhu
- first_name: Martin E.
full_name: Huber, Martin E.
last_name: Huber
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
citation:
ama: 'Serlin M, Tschirhart C, Polshyn H, Zhu J, Huber ME, Young A. Direct Imaging
of magnetic structure in twisted bilayer graphene with scanning nanoSQUID-On-Tip
microscopy. In: APS March Meeting 2019. Vol 64. American Physical Society;
2019.'
apa: 'Serlin, M., Tschirhart, C., Polshyn, H., Zhu, J., Huber, M. E., & Young,
A. (2019). Direct Imaging of magnetic structure in twisted bilayer graphene with
scanning nanoSQUID-On-Tip microscopy. In APS March Meeting 2019 (Vol. 64).
Boston, MA, United States: American Physical Society.'
chicago: Serlin, Marec, Charles Tschirhart, Hryhoriy Polshyn, Jiacheng Zhu, Martin
E. Huber, and Andrea Young. “Direct Imaging of Magnetic Structure in Twisted Bilayer
Graphene with Scanning NanoSQUID-On-Tip Microscopy.” In APS March Meeting 2019,
Vol. 64. American Physical Society, 2019.
ieee: M. Serlin, C. Tschirhart, H. Polshyn, J. Zhu, M. E. Huber, and A. Young, “Direct
Imaging of magnetic structure in twisted bilayer graphene with scanning nanoSQUID-On-Tip
microscopy,” in APS March Meeting 2019, Boston, MA, United States, 2019,
vol. 64, no. 2.
ista: 'Serlin M, Tschirhart C, Polshyn H, Zhu J, Huber ME, Young A. 2019. Direct
Imaging of magnetic structure in twisted bilayer graphene with scanning nanoSQUID-On-Tip
microscopy. APS March Meeting 2019. APS: American Physical Society, Bulletin of
the American Physical Society, vol. 64, L14.00006.'
mla: Serlin, Marec, et al. “Direct Imaging of Magnetic Structure in Twisted Bilayer
Graphene with Scanning NanoSQUID-On-Tip Microscopy.” APS March Meeting 2019,
vol. 64, no. 2, L14.00006, American Physical Society, 2019.
short: M. Serlin, C. Tschirhart, H. Polshyn, J. Zhu, M.E. Huber, A. Young, in:,
APS March Meeting 2019, American Physical Society, 2019.
conference:
end_date: 2019-03-08
location: Boston, MA, United States
name: 'APS: American Physical Society'
start_date: 2019-03-04
date_created: 2022-02-04T11:54:21Z
date_published: 2019-03-01T00:00:00Z
date_updated: 2022-02-08T10:25:30Z
day: '01'
extern: '1'
intvolume: ' 64'
issue: '2'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR19/Session/L14.6
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2019
publication_identifier:
issn:
- 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Direct Imaging of magnetic structure in twisted bilayer graphene with scanning
nanoSQUID-On-Tip microscopy
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 64
year: '2019'
...
---
_id: '10723'
abstract:
- lang: eng
text: In monolayer graphene, the interplay of electronic correlations with the internal
spin- and valley- degrees of freedom leads to a complex phase diagram of isospin
symmetry breaking at high magnetic fields. Recently, Wei et al. (Science (2018))
demonstrated that spin waves can be electrically generated and detected in graphene
heterojunctions, allowing direct experiment access to the spin degree of freedom.
Here, we apply this technique to high quality graphite-gated graphene devices
showing robust fractional quantum Hall phases and isospin phase transitions. We
use an edgeless Corbino geometry to eliminate the contributions of edge states
to the spin-wave mediated nonlocal voltage, allowing unambiguous identification
of spin wave transport signatures. Our data reveal two phases within the ν = 1
plateau. For exactly ν=1, charge is localized but spin waves propagate freely
while small carrier doping completely quenches the low-energy spin-wave transport,
even as those charges remain localized. We identify this new phase as a spin textured
electron solid. We also find that spin-wave transport is modulated by phase transitions
in the valley order that preserve spin polarization, suggesting that this technique
is sensitive to both spin and valley order.
article_number: P01.00004
article_processing_charge: No
author:
- first_name: Haoxin
full_name: Zhou, Haoxin
last_name: Zhou
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Takashi
full_name: Tanaguchi, Takashi
last_name: Tanaguchi
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
citation:
ama: 'Zhou H, Polshyn H, Tanaguchi T, Watanabe K, Young A. Spin wave transport through
electron solids and fractional quantum Hall liquids in graphene. In: APS March
Meeting 2019. Vol 64. American Physical Society; 2019.'
apa: 'Zhou, H., Polshyn, H., Tanaguchi, T., Watanabe, K., & Young, A. (2019).
Spin wave transport through electron solids and fractional quantum Hall liquids
in graphene. In APS March Meeting 2019 (Vol. 64). Boston, MA, United States:
American Physical Society.'
chicago: Zhou, Haoxin, Hryhoriy Polshyn, Takashi Tanaguchi, Kenji Watanabe, and
Andrea Young. “Spin Wave Transport through Electron Solids and Fractional Quantum
Hall Liquids in Graphene.” In APS March Meeting 2019, Vol. 64. American
Physical Society, 2019.
ieee: H. Zhou, H. Polshyn, T. Tanaguchi, K. Watanabe, and A. Young, “Spin wave transport
through electron solids and fractional quantum Hall liquids in graphene,” in APS
March Meeting 2019, Boston, MA, United States, 2019, vol. 64, no. 2.
ista: 'Zhou H, Polshyn H, Tanaguchi T, Watanabe K, Young A. 2019. Spin wave transport
through electron solids and fractional quantum Hall liquids in graphene. APS March
Meeting 2019. APS: American Physical Society vol. 64, P01.00004.'
mla: Zhou, Haoxin, et al. “Spin Wave Transport through Electron Solids and Fractional
Quantum Hall Liquids in Graphene.” APS March Meeting 2019, vol. 64, no.
2, P01.00004, American Physical Society, 2019.
short: H. Zhou, H. Polshyn, T. Tanaguchi, K. Watanabe, A. Young, in:, APS March
Meeting 2019, American Physical Society, 2019.
conference:
end_date: 2019-03-08
location: Boston, MA, United States
name: 'APS: American Physical Society'
start_date: 2019-03-04
date_created: 2022-02-04T12:14:02Z
date_published: 2019-03-01T00:00:00Z
date_updated: 2022-02-04T13:59:47Z
day: '01'
extern: '1'
intvolume: ' 64'
issue: '2'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR19/Session/P01.4
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2019
publication_identifier:
issn:
- 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Spin wave transport through electron solids and fractional quantum Hall liquids
in graphene
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 64
year: '2019'
...
---
_id: '10724'
abstract:
- lang: eng
text: Twisted bilayer graphene (tBLG) near the flat band condition is a versatile
new platform for the study of correlated physics in 2D. Resistive states have
been observed at several commensurate fillings of the flat miniband, along with
superconducting states near half filling. To better understand the electronic
structure of this system, we study electronic transport of graphite gated superconducting
tBLG devices in the normal regime. At high magnetic fields, we observe full lifting
of the spin and valley degeneracy. The transitions in the splitting of this four-fold
degeneracy as a function of carrier density indicate Landau level (LL) crossings,
which tilted field measurements show occur between LLs with different valley polarization.
Similar LL structure measured in two devices, one with twist angle θ=1.08° at
ambient pressure and one at θ=1.27° and 1.33GPa, suggests that the dimensionless
combination of twist angle and interlayer coupling controls the relevant details
of the band structure. In addition, we find that the temperature dependence of
the resistance at B=0 shows linear growth at several hundred Ohm/K in a broad
range of temperatures. We discuss the implications for modeling the scattering
processes in this system.
alternative_title:
- Bulletin of the American Physical Society
article_number: V14.00008
article_processing_charge: No
author:
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Yuxuan
full_name: Zhang, Yuxuan
last_name: Zhang
- first_name: Matthew
full_name: Yankowitz, Matthew
last_name: Yankowitz
- first_name: Shaowen
full_name: Chen, Shaowen
last_name: Chen
- first_name: Takashi
full_name: Taniguchi, Takashi
last_name: Taniguchi
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: David E.
full_name: Graf, David E.
last_name: Graf
- first_name: Cory R.
full_name: Dean, Cory R.
last_name: Dean
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
citation:
ama: 'Polshyn H, Zhang Y, Yankowitz M, et al. Normal state transport in superconducting
twisted bilayer graphene. In: APS March Meeting 2019. Vol 64. American
Physical Society; 2019.'
apa: 'Polshyn, H., Zhang, Y., Yankowitz, M., Chen, S., Taniguchi, T., Watanabe,
K., … Young, A. (2019). Normal state transport in superconducting twisted bilayer
graphene. In APS March Meeting 2019 (Vol. 64). Boston, MA, United States:
American Physical Society.'
chicago: Polshyn, Hryhoriy, Yuxuan Zhang, Matthew Yankowitz, Shaowen Chen, Takashi
Taniguchi, Kenji Watanabe, David E. Graf, Cory R. Dean, and Andrea Young. “Normal
State Transport in Superconducting Twisted Bilayer Graphene.” In APS March
Meeting 2019, Vol. 64. American Physical Society, 2019.
ieee: H. Polshyn et al., “Normal state transport in superconducting twisted
bilayer graphene,” in APS March Meeting 2019, Boston, MA, United States,
2019, vol. 64, no. 2.
ista: 'Polshyn H, Zhang Y, Yankowitz M, Chen S, Taniguchi T, Watanabe K, Graf DE,
Dean CR, Young A. 2019. Normal state transport in superconducting twisted bilayer
graphene. APS March Meeting 2019. APS: American Physical Society, Bulletin of
the American Physical Society, vol. 64, V14.00008.'
mla: Polshyn, Hryhoriy, et al. “Normal State Transport in Superconducting Twisted
Bilayer Graphene.” APS March Meeting 2019, vol. 64, no. 2, V14.00008, American
Physical Society, 2019.
short: H. Polshyn, Y. Zhang, M. Yankowitz, S. Chen, T. Taniguchi, K. Watanabe, D.E.
Graf, C.R. Dean, A. Young, in:, APS March Meeting 2019, American Physical Society,
2019.
conference:
end_date: 2019-03-08
location: Boston, MA, United States
name: 'APS: American Physical Society'
start_date: 2019-03-04
date_created: 2022-02-04T12:25:04Z
date_published: 2019-03-01T00:00:00Z
date_updated: 2022-02-08T10:23:13Z
day: '01'
extern: '1'
intvolume: ' 64'
issue: '2'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR19/Session/V14.8
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2019
publication_identifier:
issn:
- 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Normal state transport in superconducting twisted bilayer graphene
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 64
year: '2019'
...
---
_id: '10725'
abstract:
- lang: eng
text: Bilayer graphene with ~ 1.1 degrees twist mismatch between the layers hosts
a low energy flat band in which the Coulomb interaction is large relative to the
bandwidth, promoting correlated insulating states at half band filling, and superconducting
(SC) phases with dome-like structure neighboring correlated insulating states.
Here we show measurements of a dual-graphite-gated twisted bilayer graphene device,
which minimizes charge inhomogeneity. We observe new correlated phases, including
for the first time a SC pocket near half-filling of the electron-doped band and
resistive states at quarter-filling of both bands that emerge in a magnetic field.
Changing the layer polarization with vertical electric field reveals an unexpected
competition between SC and correlated insulator phases, which we interpret to
result from differences in disorder of each graphene layer and underscores the
spatial inhomogeneity like twist angle as a significant source of disorder in
these devices [1].
alternative_title:
- Bulletin of the American Physical Society
article_number: R14.00004
article_processing_charge: No
author:
- first_name: Shaowen
full_name: Chen, Shaowen
last_name: Chen
- first_name: Matthew
full_name: Yankowitz, Matthew
last_name: Yankowitz
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Kenji
full_name: Watanabe, Kenji
last_name: Watanabe
- first_name: Takashi
full_name: Taniguchi, Takashi
last_name: Taniguchi
- first_name: David E.
full_name: Graf, David E.
last_name: Graf
- first_name: Andrea
full_name: Young, Andrea
last_name: Young
- first_name: Cory R.
full_name: Dean, Cory R.
last_name: Dean
citation:
ama: 'Chen S, Yankowitz M, Polshyn H, et al. Correlated insulating and superconducting
phases in twisted bilayer graphene. In: APS March Meeting 2019. Vol 64.
American Physical Society; 2019.'
apa: 'Chen, S., Yankowitz, M., Polshyn, H., Watanabe, K., Taniguchi, T., Graf, D.
E., … Dean, C. R. (2019). Correlated insulating and superconducting phases in
twisted bilayer graphene. In APS March Meeting 2019 (Vol. 64). Boston,
MA, United States: American Physical Society.'
chicago: Chen, Shaowen, Matthew Yankowitz, Hryhoriy Polshyn, Kenji Watanabe, Takashi
Taniguchi, David E. Graf, Andrea Young, and Cory R. Dean. “Correlated Insulating
and Superconducting Phases in Twisted Bilayer Graphene.” In APS March Meeting
2019, Vol. 64. American Physical Society, 2019.
ieee: S. Chen et al., “Correlated insulating and superconducting phases in
twisted bilayer graphene,” in APS March Meeting 2019, Boston, MA, United
States, 2019, vol. 64, no. 2.
ista: 'Chen S, Yankowitz M, Polshyn H, Watanabe K, Taniguchi T, Graf DE, Young A,
Dean CR. 2019. Correlated insulating and superconducting phases in twisted bilayer
graphene. APS March Meeting 2019. APS: American Physical Society, Bulletin of
the American Physical Society, vol. 64, R14.00004.'
mla: Chen, Shaowen, et al. “Correlated Insulating and Superconducting Phases in
Twisted Bilayer Graphene.” APS March Meeting 2019, vol. 64, no. 2, R14.00004,
American Physical Society, 2019.
short: S. Chen, M. Yankowitz, H. Polshyn, K. Watanabe, T. Taniguchi, D.E. Graf,
A. Young, C.R. Dean, in:, APS March Meeting 2019, American Physical Society, 2019.
conference:
end_date: 2019-03-08
location: Boston, MA, United States
name: 'APS: American Physical Society'
start_date: 2019-03-04
date_created: 2022-02-04T13:48:04Z
date_published: 2019-03-01T00:00:00Z
date_updated: 2022-02-08T10:24:13Z
day: '01'
extern: '1'
intvolume: ' 64'
issue: '2'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://meetings.aps.org/Meeting/MAR19/Session/R14.4
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2019
publication_identifier:
issn:
- 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
related_material:
link:
- relation: used_in_publication
url: https://arxiv.org/abs/1808.07865
status: public
title: Correlated insulating and superconducting phases in twisted bilayer graphene
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 64
year: '2019'
...
---
_id: '10619'
abstract:
- lang: eng
text: The quantum anomalous Hall (QAH) effect combines topology and magnetism to
produce precisely quantized Hall resistance at zero magnetic field. We report
the observation of a QAH effect in twisted bilayer graphene aligned to hexagonal
boron nitride. The effect is driven by intrinsic strong interactions, which polarize
the electrons into a single spin- and valley-resolved moiré miniband with Chern
number C = 1. In contrast to magnetically doped systems, the measured transport
energy gap is larger than the Curie temperature for magnetic ordering, and quantization
to within 0.1% of the von Klitzing constant persists to temperatures of several
kelvin at zero magnetic field. Electrical currents as small as 1 nanoampere controllably
switch the magnetic order between states of opposite polarization, forming an
electrically rewritable magnetic memory.
acknowledgement: The authors acknowledge discussions with A. Macdonald, Y. Saito,
and M. Zaletel.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: M.
full_name: Serlin, M.
last_name: Serlin
- first_name: C. L.
full_name: Tschirhart, C. L.
last_name: Tschirhart
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: Y.
full_name: Zhang, Y.
last_name: Zhang
- first_name: J.
full_name: Zhu, J.
last_name: Zhu
- first_name: K.
full_name: Watanabe, K.
last_name: Watanabe
- first_name: T.
full_name: Taniguchi, T.
last_name: Taniguchi
- first_name: L.
full_name: Balents, L.
last_name: Balents
- first_name: A. F.
full_name: Young, A. F.
last_name: Young
citation:
ama: Serlin M, Tschirhart CL, Polshyn H, et al. Intrinsic quantized anomalous Hall
effect in a moiré heterostructure. Science. 2019;367(6480):900-903. doi:10.1126/science.aay5533
apa: Serlin, M., Tschirhart, C. L., Polshyn, H., Zhang, Y., Zhu, J., Watanabe, K.,
… Young, A. F. (2019). Intrinsic quantized anomalous Hall effect in a moiré heterostructure.
Science. American Association for the Advancement of Science. https://doi.org/10.1126/science.aay5533
chicago: Serlin, M., C. L. Tschirhart, Hryhoriy Polshyn, Y. Zhang, J. Zhu, K. Watanabe,
T. Taniguchi, L. Balents, and A. F. Young. “Intrinsic Quantized Anomalous Hall
Effect in a Moiré Heterostructure.” Science. American Association for the
Advancement of Science, 2019. https://doi.org/10.1126/science.aay5533.
ieee: M. Serlin et al., “Intrinsic quantized anomalous Hall effect in a moiré
heterostructure,” Science, vol. 367, no. 6480. American Association for
the Advancement of Science, pp. 900–903, 2019.
ista: Serlin M, Tschirhart CL, Polshyn H, Zhang Y, Zhu J, Watanabe K, Taniguchi
T, Balents L, Young AF. 2019. Intrinsic quantized anomalous Hall effect in a moiré
heterostructure. Science. 367(6480), 900–903.
mla: Serlin, M., et al. “Intrinsic Quantized Anomalous Hall Effect in a Moiré Heterostructure.”
Science, vol. 367, no. 6480, American Association for the Advancement of
Science, 2019, pp. 900–03, doi:10.1126/science.aay5533.
short: M. Serlin, C.L. Tschirhart, H. Polshyn, Y. Zhang, J. Zhu, K. Watanabe, T.
Taniguchi, L. Balents, A.F. Young, Science 367 (2019) 900–903.
date_created: 2022-01-13T14:21:32Z
date_published: 2019-12-19T00:00:00Z
date_updated: 2023-02-21T16:00:09Z
day: '19'
doi: 10.1126/science.aay5533
extern: '1'
external_id:
arxiv:
- '1907.00261'
pmid:
- '31857492'
intvolume: ' 367'
issue: '6480'
keyword:
- multidisciplinary
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1907.00261
month: '12'
oa: 1
oa_version: Preprint
page: 900-903
pmid: 1
publication: Science
publication_identifier:
eissn:
- 1095-9203
issn:
- 0036-8075
publication_status: published
publisher: American Association for the Advancement of Science
quality_controlled: '1'
related_material:
record:
- id: '10697'
relation: other
status: public
- id: '10698'
relation: other
status: public
- id: '10699'
relation: other
status: public
scopus_import: '1'
status: public
title: Intrinsic quantized anomalous Hall effect in a moiré heterostructure
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 367
year: '2019'
...
---
_id: '10620'
abstract:
- lang: eng
text: Partially filled Landau levels host competing electronic orders. For example,
electron solids may prevail close to integer filling of the Landau levels before
giving way to fractional quantum Hall liquids at higher carrier density1,2. Here,
we report the observation of an electron solid with non-collinear spin texture
in monolayer graphene, consistent with solidification of skyrmions3—topological
spin textures characterized by quantized electrical charge4,5. We probe the spin
texture of the solids using a modified Corbino geometry that allows ferromagnetic
magnons to be launched and detected6,7. We find that magnon transport is highly
efficient when one Landau level is filled (ν=1), consistent with quantum Hall
ferromagnetic spin polarization. However, even minimal doping immediately quenches
the magnon signal while leaving the vanishing low-temperature charge conductivity
unchanged. Our results can be understood by the formation of a solid of charged
skyrmions near ν=1, whose non-collinear spin texture leads to rapid magnon decay.
Data near fractional fillings show evidence of several fractional skyrmion solids,
suggesting that graphene hosts a highly tunable landscape of coupled spin and
charge orders.
acknowledgement: We acknowledge discussions with B. Halperin, C. Huang, A. Macdonald
and M. Zalatel. Experimental work at UCSB was supported by the Army Research Office
under awards nos. MURI W911NF-16-1-0361 and W911NF-16-1-0482. K.W. and T.T. acknowledge
support from the Elemental Strategy Initiative conducted by MEXT (Japan) and CREST
(JPMJCR15F3), JST. A.F.Y. acknowledges the support of the David and Lucile Packard
Foundation and and Alfred. P. Sloan Foundation.
article_processing_charge: No
article_type: original
author:
- first_name: H.
full_name: Zhou, H.
last_name: Zhou
- first_name: Hryhoriy
full_name: Polshyn, Hryhoriy
id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
last_name: Polshyn
orcid: 0000-0001-8223-8896
- first_name: T.
full_name: Taniguchi, T.
last_name: Taniguchi
- first_name: K.
full_name: Watanabe, K.
last_name: Watanabe
- first_name: A. F.
full_name: Young, A. F.
last_name: Young
citation:
ama: Zhou H, Polshyn H, Taniguchi T, Watanabe K, Young AF. Solids of quantum Hall
skyrmions in graphene. Nature Physics. 2019;16(2):154-158. doi:10.1038/s41567-019-0729-8
apa: Zhou, H., Polshyn, H., Taniguchi, T., Watanabe, K., & Young, A. F. (2019).
Solids of quantum Hall skyrmions in graphene. Nature Physics. Springer
Nature. https://doi.org/10.1038/s41567-019-0729-8
chicago: Zhou, H., Hryhoriy Polshyn, T. Taniguchi, K. Watanabe, and A. F. Young.
“Solids of Quantum Hall Skyrmions in Graphene.” Nature Physics. Springer
Nature, 2019. https://doi.org/10.1038/s41567-019-0729-8.
ieee: H. Zhou, H. Polshyn, T. Taniguchi, K. Watanabe, and A. F. Young, “Solids of
quantum Hall skyrmions in graphene,” Nature Physics, vol. 16, no. 2. Springer
Nature, pp. 154–158, 2019.
ista: Zhou H, Polshyn H, Taniguchi T, Watanabe K, Young AF. 2019. Solids of quantum
Hall skyrmions in graphene. Nature Physics. 16(2), 154–158.
mla: Zhou, H., et al. “Solids of Quantum Hall Skyrmions in Graphene.” Nature
Physics, vol. 16, no. 2, Springer Nature, 2019, pp. 154–58, doi:10.1038/s41567-019-0729-8.
short: H. Zhou, H. Polshyn, T. Taniguchi, K. Watanabe, A.F. Young, Nature Physics
16 (2019) 154–158.
date_created: 2022-01-13T14:45:16Z
date_published: 2019-12-16T00:00:00Z
date_updated: 2022-01-13T15:34:44Z
day: '16'
doi: 10.1038/s41567-019-0729-8
extern: '1'
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issue: '2'
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- General Physics and Astronomy
language:
- iso: eng
month: '12'
oa_version: None
page: 154-158
publication: Nature Physics
publication_identifier:
eissn:
- 1745-2481
issn:
- 1745-2473
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
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status: public
title: Solids of quantum Hall skyrmions in graphene
type: journal_article
user_id: ea97e931-d5af-11eb-85d4-e6957dddbf17
volume: 16
year: '2019'
...