---
_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: <i>APS March Meeting 2021</i>. 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 <i>APS March Meeting
    2021</i> (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 <i>APS March Meeting 2021</i>, Vol. 66. American Physical Society,
    2021.
  ieee: H. Polshyn <i>et al.</i>, “Orbital Chern insulator states in twisted monolayer-bilayer
    graphene and electrical switching of topological and magnetic order,” in <i>APS
    March Meeting 2021</i>, 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.” <i>APS March
    Meeting 2021</i>, 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: '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: <i>APS March Meeting 2021</i>. 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 <i>APS March Meeting 2021</i> (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 <i>APS March Meeting 2021</i>, Vol. 66. American
    Physical Society, 2021.
  ieee: C. Tschirhart <i>et al.</i>, “Probing orbital Chern ferromagnet phase in twisted
    bilayer graphene,” in <i>APS March Meeting 2021</i>, 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.” <i>APS March Meeting 2021</i>, 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: <i>APS March Meeting 2020</i>. Vol 65. American Physical Society; 2020.'
  apa: 'Zhou, H., Polshyn, H., Tanaguchi, T., Watanabe, K., &#38; Young, A. (2020).
    Sublattice resolved spin wave transport through graphene fractional quantum Hall
    states as a probe of isospin order. In <i>APS March Meeting 2020</i> (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 <i>APS March Meeting 2020</i>,
    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 <i>APS March Meeting 2020</i>, 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.” <i>APS March Meeting
    2020</i>, 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: <i>APS March
    Meeting 2020</i>. Vol 65. American Physical Society; 2020.'
  apa: 'Polshyn, H., Zhu, J., Kumar, M., Taniguchi, T., Watanabe, K., MacDonald, A.,
    &#38; Young, A. (2020). Correlated states and tunable topological bands in twisted
    monolayer-bilayer graphene heterostructures. In <i>APS March Meeting 2020</i>
    (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 <i>APS March
    Meeting 2020</i>, Vol. 65. American Physical Society, 2020.
  ieee: H. Polshyn <i>et al.</i>, “Correlated states and tunable topological bands
    in twisted monolayer-bilayer graphene heterostructures,” in <i>APS March Meeting
    2020</i>, 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.” <i>APS March Meeting
    2020</i>, 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: '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:
    <i>APS March Meeting 2020</i>. 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 <i>APS March Meeting 2020</i> (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 <i>APS March Meeting 2020</i>, Vol.
    65. American Physical Society, 2020.'
  ieee: 'C. Tschirhart <i>et al.</i>, “Intrinsic quantized anomalous Hall effect in
    a moiré heterostructure, part III: Scanning probe magnetometry,” in <i>APS March
    Meeting 2020</i>, 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.” <i>APS March
    Meeting 2020</i>, 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: '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: <i>APS March Meeting 2019</i>. Vol 64. American Physical Society;
    2019.'
  apa: 'Serlin, M., Tschirhart, C., Polshyn, H., Zhu, J., Huber, M. E., &#38; Young,
    A. (2019). Direct Imaging of magnetic structure in twisted bilayer graphene with
    scanning nanoSQUID-On-Tip microscopy. In <i>APS March Meeting 2019</i> (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 <i>APS March Meeting 2019</i>,
    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 <i>APS March Meeting 2019</i>, 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.” <i>APS March Meeting 2019</i>,
    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: <i>APS March
    Meeting 2019</i>. Vol 64. American Physical Society; 2019.'
  apa: 'Zhou, H., Polshyn, H., Tanaguchi, T., Watanabe, K., &#38; Young, A. (2019).
    Spin wave transport through electron solids and fractional quantum Hall liquids
    in graphene. In <i>APS March Meeting 2019</i> (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 <i>APS March Meeting 2019</i>, 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 <i>APS
    March Meeting 2019</i>, 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.” <i>APS March Meeting 2019</i>, 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: <i>APS March Meeting 2019</i>. 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 <i>APS March Meeting 2019</i> (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 <i>APS March
    Meeting 2019</i>, Vol. 64. American Physical Society, 2019.
  ieee: H. Polshyn <i>et al.</i>, “Normal state transport in superconducting twisted
    bilayer graphene,” in <i>APS March Meeting 2019</i>, 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.” <i>APS March Meeting 2019</i>, 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: <i>APS March Meeting 2019</i>. 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 <i>APS March Meeting 2019</i> (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 <i>APS March Meeting
    2019</i>, Vol. 64. American Physical Society, 2019.
  ieee: S. Chen <i>et al.</i>, “Correlated insulating and superconducting phases in
    twisted bilayer graphene,” in <i>APS March Meeting 2019</i>, 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.” <i>APS March Meeting 2019</i>, 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: '10745'
abstract:
- lang: eng
  text: New ways to investigate and manipulate fluxoid and vortex states of mesoscopic
    superconducting structures are of great interest. The states with multiple vortices
    or winding numbers could be useful for the study of vortex interactions and interference
    effects, the braiding of Majorana bound states by winding vortices, and the development
    of novel superconducting devices. We demonstrate a methodology based on magnetic
    force microscopy that allows us to induce, probe and control fluxoid states in
    thin wall structures comprised of multiple loops. By using micro-magnet as a source
    of inhomogeneous magnetic field, we can efficiently explore the configuration
    space of fluxoid states. Scanning over the structure reveals the energy crossing
    points of the lowest laying fluxoid states. This is due the strong interaction
    of cantilever with thermally activated fluxoid transitions at points of degeneracy.
    We show that measured patterns of fluxoid transitions allow to identify the states,
    investigate their energetics, and manipulate them. Further, we show that the dynamics
    of driven fluxoid transitions can be described by stochastic resonance model,
    which provides a unique way of measuring fluxoid transition rate and related energy
    barrier for chosen transitions even in complicated structures
alternative_title:
- Bulletin of the American Physical Society
article_number: P39.00011
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: Tyler
  full_name: Naibert, Tyler
  last_name: Naibert
- first_name: Raffi
  full_name: Budakian, Raffi
  last_name: Budakian
citation:
  ama: 'Polshyn H, Naibert T, Budakian R.  Probing and controlling fluxoid states
    in multiply-connected mesoscopic superconducting structures. In: <i>APS March
    Meeting 2017</i>. Vol 62. American Physical Society; 2017.'
  apa: 'Polshyn, H., Naibert, T., &#38; Budakian, R. (2017).  Probing and controlling
    fluxoid states in multiply-connected mesoscopic superconducting structures. In
    <i>APS March Meeting 2017</i> (Vol. 62). New Orleans, LA, United States: American
    Physical Society.'
  chicago: Polshyn, Hryhoriy, Tyler Naibert, and Raffi Budakian. “ Probing and Controlling
    Fluxoid States in Multiply-Connected Mesoscopic Superconducting Structures.” In
    <i>APS March Meeting 2017</i>, Vol. 62. American Physical Society, 2017.
  ieee: H. Polshyn, T. Naibert, and R. Budakian, “ Probing and controlling fluxoid
    states in multiply-connected mesoscopic superconducting structures,” in <i>APS
    March Meeting 2017</i>, New Orleans, LA, United States, 2017, vol. 62, no. 4.
  ista: 'Polshyn H, Naibert T, Budakian R. 2017.  Probing and controlling fluxoid
    states in multiply-connected mesoscopic superconducting structures. APS March
    Meeting 2017. APS: American Physical Society, Bulletin of the American Physical
    Society, vol. 62, P39.00011.'
  mla: Polshyn, Hryhoriy, et al. “ Probing and Controlling Fluxoid States in Multiply-Connected
    Mesoscopic Superconducting Structures.” <i>APS March Meeting 2017</i>, vol. 62,
    no. 4, P39.00011, American Physical Society, 2017.
  short: H. Polshyn, T. Naibert, R. Budakian, in:, APS March Meeting 2017, American
    Physical Society, 2017.
conference:
  end_date: 2017-03-17
  location: New Orleans, LA, United States
  name: 'APS: American Physical Society'
  start_date: 2017-03-13
date_created: 2022-02-08T09:49:17Z
date_published: 2017-03-01T00:00:00Z
date_updated: 2022-02-08T10:44:35Z
day: '01'
extern: '1'
intvolume: '        62'
issue: '4'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://meetings.aps.org/Meeting/MAR17/Session/P39.11
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2017
publication_identifier:
  issn:
  - 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: ' Probing and controlling fluxoid states in multiply-connected mesoscopic superconducting
  structures'
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 62
year: '2017'
...
---
_id: '10746'
abstract:
- lang: eng
  text: Vortex states in superconducting (SC) structures, their dynamics and ways
    to manipulate them are topics of great interest. We report a new method of magnetic
    force microscopy (MFM) that allows the study of vortex states in mesoscopic SC
    samples. For the case of a SC ring, which is biased to a half-integer flux quantum,
    the flux modulation through the ring caused by the motion of the magnetic tip
    drives the ring between two consecutive fluxoid states. The corresponding current
    switching in the ring produces strong position-dependent forces on the cantilever.
    In the regime where the frequency of the thermally activated jumps between fluxoid
    states is close to the frequency of the cantilever, large changes in the cantilever
    frequency and dissipation are observed. This effect may be understood as a stochastic
    resonance (SR) process. These changes in the cantilever’s mechanical properties
    are used to “image” the barrier energies between fluxoid states. Additionally,
    SR imaging of the barrier energies are used to study the effect of the locally
    applied magnetic field from the MFM tip on the barrier heights. We report the
    results of measurements for Al rings. Further, the same imaging technique can
    be applied to more sophisticated SC structures such as arrays of Josephson junctions.
alternative_title:
- Bulletin of the American Physical Society
article_number: E25.00007
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: Tyler
  full_name: Naibert, Tyler
  last_name: Naibert
- first_name: Victor
  full_name: Chua, Victor
  last_name: Chua
- first_name: Raffi
  full_name: Budakian, Raffi
  last_name: Budakian
citation:
  ama: 'Polshyn H, Naibert T, Chua V, Budakian R. Study of vortex states and dynamics
    in mesoscopic superconducting samples with MFM. In: <i>APS March Meeting 2016</i>.
    Vol 61. American Physical Society; 2016.'
  apa: 'Polshyn, H., Naibert, T., Chua, V., &#38; Budakian, R. (2016). Study of vortex
    states and dynamics in mesoscopic superconducting samples with MFM. In <i>APS
    March Meeting 2016</i> (Vol. 61). Baltimore, MD, United States: American Physical
    Society.'
  chicago: Polshyn, Hryhoriy, Tyler Naibert, Victor Chua, and Raffi Budakian. “Study
    of Vortex States and Dynamics in Mesoscopic Superconducting Samples with MFM.”
    In <i>APS March Meeting 2016</i>, Vol. 61. American Physical Society, 2016.
  ieee: H. Polshyn, T. Naibert, V. Chua, and R. Budakian, “Study of vortex states
    and dynamics in mesoscopic superconducting samples with MFM,” in <i>APS March
    Meeting 2016</i>, Baltimore, MD, United States, 2016, vol. 61, no. 2.
  ista: 'Polshyn H, Naibert T, Chua V, Budakian R. 2016. Study of vortex states and
    dynamics in mesoscopic superconducting samples with MFM. APS March Meeting 2016.
    APS: American Physical Society, Bulletin of the American Physical Society, vol.
    61, E25.00007.'
  mla: Polshyn, Hryhoriy, et al. “Study of Vortex States and Dynamics in Mesoscopic
    Superconducting Samples with MFM.” <i>APS March Meeting 2016</i>, vol. 61, no.
    2, E25.00007, American Physical Society, 2016.
  short: H. Polshyn, T. Naibert, V. Chua, R. Budakian, in:, APS March Meeting 2016,
    American Physical Society, 2016.
conference:
  end_date: 2016-03-18
  location: Baltimore, MD, United States
  name: 'APS: American Physical Society'
  start_date: 2016-03-14
date_created: 2022-02-08T09:55:09Z
date_published: 2016-03-01T00:00:00Z
date_updated: 2022-02-08T10:44:06Z
day: '01'
extern: '1'
intvolume: '        61'
issue: '2'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://meetings.aps.org/Meeting/MAR16/Session/E25.7
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2016
publication_identifier:
  issn:
  - 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Study of vortex states and dynamics in mesoscopic superconducting samples with
  MFM
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 61
year: '2016'
...
---
_id: '10747'
abstract:
- lang: eng
  text: Vortex interactions are key to explaining the behavior of many two dimensional
    superconducting systems. We report on the development of a technique to locally
    probe vortex interactions in a 2D array of Josephson junctions. Scanning a magnetic
    tip attached to an ultra-soft cantilever over the array produces changes in the
    frequency of the cantilever along certain lines, forming geometric patterns in
    the scans. Different tip-surface separations and external magnetic fields produce
    a number of different patterns. These patterns correspond to tip locations in
    which two configurations of vortices in the lattice have degenerate energies.
    By imaging the locations of these degeneracies, information on the local vortex
    interactions may be obtained.
alternative_title:
- Bulletin of the American Physical Society
article_number: H25.00006
article_processing_charge: No
author:
- first_name: Tyler
  full_name: Naibert, Tyler
  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: Brian
  full_name: Wolin, Brian
  last_name: Wolin
- first_name: Malcolm
  full_name: Durkin, Malcolm
  last_name: Durkin
- first_name: Rita
  full_name: Garrido Menacho, Rita
  last_name: Garrido Menacho
- first_name: Ian Mondragon
  full_name: Shem, Ian Mondragon
  last_name: Shem
- first_name: Victor
  full_name: Chua, Victor
  last_name: Chua
- 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 T, Polshyn H, Wolin B, et al. Stochastic resonance magnetic force
    microscopy imaging of Josephson arrays. In: <i>APS March Meeting 2016</i>. Vol
    61. American Physical Society; 2016.'
  apa: 'Naibert, T., Polshyn, H., Wolin, B., Durkin, M., Garrido Menacho, R., Shem,
    I. M., … Budakian, R. (2016). Stochastic resonance magnetic force microscopy imaging
    of Josephson arrays. In <i>APS March Meeting 2016</i> (Vol. 61). Baltimore, MD,
    United States: American Physical Society.'
  chicago: Naibert, Tyler, Hryhoriy Polshyn, Brian Wolin, Malcolm Durkin, Rita Garrido
    Menacho, Ian Mondragon Shem, Victor Chua, Taylor Hughes, Nadya Mason, and Raffi
    Budakian. “Stochastic Resonance Magnetic Force Microscopy Imaging of Josephson
    Arrays.” In <i>APS March Meeting 2016</i>, Vol. 61. American Physical Society,
    2016.
  ieee: T. Naibert <i>et al.</i>, “Stochastic resonance magnetic force microscopy
    imaging of Josephson arrays,” in <i>APS March Meeting 2016</i>, Baltimore, MD,
    United States, 2016, vol. 61, no. 2.
  ista: 'Naibert T, Polshyn H, Wolin B, Durkin M, Garrido Menacho R, Shem IM, Chua
    V, Hughes T, Mason N, Budakian R. 2016. Stochastic resonance magnetic force microscopy
    imaging of Josephson arrays. APS March Meeting 2016. APS: American Physical Society,
    Bulletin of the American Physical Society, vol. 61, H25.00006.'
  mla: Naibert, Tyler, et al. “Stochastic Resonance Magnetic Force Microscopy Imaging
    of Josephson Arrays.” <i>APS March Meeting 2016</i>, vol. 61, no. 2, H25.00006,
    American Physical Society, 2016.
  short: T. Naibert, H. Polshyn, B. Wolin, M. Durkin, R. Garrido Menacho, I.M. Shem,
    V. Chua, T. Hughes, N. Mason, R. Budakian, in:, APS March Meeting 2016, American
    Physical Society, 2016.
conference:
  end_date: 2016-03-18
  location: Baltimore, MD, United States
  name: 'APS: American Physical Society'
  start_date: 2016-03-14
date_created: 2022-02-08T10:10:39Z
date_published: 2016-03-01T00:00:00Z
date_updated: 2022-02-08T10:43:33Z
day: '01'
extern: '1'
intvolume: '        61'
issue: '2'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://meetings.aps.org/Meeting/MAR16/Session/H25.6
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2016
publication_identifier:
  issn:
  - 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Stochastic resonance magnetic force microscopy imaging of Josephson arrays
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 61
year: '2016'
...
---
_id: '10748'
abstract:
- lang: eng
  text: The study of fluxoid states and fluxoid dynamics in mesoscopic iron-based
    superconducting rings is valuable for characterizing the basic properties of the
    superconductor, and may also provide important insight into the superconducting
    paring symmetry. We report the fabrications of micron-sized rings and disks from
    thin films of Fe(Se, Te) grown by molecular beam epitaxy. In order to study fluxoid
    states in rings we developed a custom-tailored version of magnetic force microscopy
    (MFM). This technique has a number of qualitative advantages for working with
    mesoscopic superconducting samples in comparison to the conventional MFM and other
    imaging techniques. We observed metastable fluxoid states in rings of different
    sizes. Thermally activated fluxoid dynamics of these states was studied and modeled.
    In addition, we found different regimes of interaction between Fe(Se, Te) ring
    and MFM tip which are explained. Possibilities of the existence of exotic vortex
    states and proposals for experiments to test the symmetry of the superconducting
    order parameter in iron based superconductors are analyzed.
alternative_title:
- Bulletin of the American Physical Society
article_number: G16.00009
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: Can
  full_name: Zhang, Can
  last_name: Zhang
- first_name: Tyler
  full_name: Naibert, Tyler
  last_name: Naibert
- first_name: James
  full_name: Eckstein, James
  last_name: Eckstein
- first_name: Raffi
  full_name: Budakian, Raffi
  last_name: Budakian
citation:
  ama: 'Polshyn H, Zhang C, Naibert T, Eckstein J, Budakian R. Study of Fe (Se, Te)
    micron-sized rings by magnetic force microscopy. In: <i>APS March Meeting 2015</i>.
    Vol 60. American Physical Society; 2015.'
  apa: 'Polshyn, H., Zhang, C., Naibert, T., Eckstein, J., &#38; Budakian, R. (2015).
    Study of Fe (Se, Te) micron-sized rings by magnetic force microscopy. In <i>APS
    March Meeting 2015</i> (Vol. 60). San Antonio, TX, United States: American Physical
    Society.'
  chicago: Polshyn, Hryhoriy, Can Zhang, Tyler Naibert, James Eckstein, and Raffi
    Budakian. “Study of Fe (Se, Te) Micron-Sized Rings by Magnetic Force Microscopy.”
    In <i>APS March Meeting 2015</i>, Vol. 60. American Physical Society, 2015.
  ieee: H. Polshyn, C. Zhang, T. Naibert, J. Eckstein, and R. Budakian, “Study of
    Fe (Se, Te) micron-sized rings by magnetic force microscopy,” in <i>APS March
    Meeting 2015</i>, San Antonio, TX, United States, 2015, vol. 60, no. 1.
  ista: 'Polshyn H, Zhang C, Naibert T, Eckstein J, Budakian R. 2015. Study of Fe
    (Se, Te) micron-sized rings by magnetic force microscopy. APS March Meeting 2015.
    APS: American Physical Society, Bulletin of the American Physical Society, vol.
    60, G16.00009.'
  mla: Polshyn, Hryhoriy, et al. “Study of Fe (Se, Te) Micron-Sized Rings by Magnetic
    Force Microscopy.” <i>APS March Meeting 2015</i>, vol. 60, no. 1, G16.00009, American
    Physical Society, 2015.
  short: H. Polshyn, C. Zhang, T. Naibert, J. Eckstein, R. Budakian, in:, APS March
    Meeting 2015, American Physical Society, 2015.
conference:
  end_date: 2015-03-06
  location: San Antonio, TX, United States
  name: 'APS: American Physical Society'
  start_date: 2015-03-02
date_created: 2022-02-08T10:17:09Z
date_published: 2015-03-01T00:00:00Z
date_updated: 2022-02-08T10:42:53Z
day: '01'
extern: '1'
intvolume: '        60'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://meetings.aps.org/Meeting/MAR15/Event/238442
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2015
publication_identifier:
  issn:
  - 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Study of Fe (Se, Te) micron-sized rings by magnetic force microscopy
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 60
year: '2015'
...
---
_id: '10749'
abstract:
- lang: eng
  text: Fluxoid quantization provides a direct means to study phase coherence. In
    cuprate superconductors, there have been observations which suggest that phase
    coherent superconducting fluctuations may persist at temperatures significantly
    above Tc. The focus of this work is to study the vortex states in mesoscopic cuprate
    superconducting samples to directly probe phase coherence over a wide range of
    temperatures. We present cantilever torque susceptometry measurements of micron
    and sub-micron size Bi2212 rings and disks. The high sensitivity of this technique
    allowed observation of transitions between different fluxoid states of a single
    ring, and the discrete vortex states of micron size disks. The dependence of magnetic
    susceptibility on diameter and wall thickness of the ring was investigated. Measurements
    were made at different values of the in-plane magnetic field, and over a wide
    range of temperatures.
acknowledgement: This work was supported by the Center for Emergent Superconductivity,
  an Energy Frontier Research Center funded by the US DOE, Office of Science.
alternative_title:
- Bulletin of the American Physical Society
article_number: N36.00001
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: Raffi
  full_name: Budakian, Raffi
  last_name: Budakian
- first_name: Genda
  full_name: Gu, Genda
  last_name: Gu
citation:
  ama: 'Polshyn H, Budakian R, Gu G. Cantilever micro-susceptometry of mesoscopic
    Bi2212 samples. In: <i>APS March Meeting 2013</i>. Vol 58. American Physical Society;
    2013.'
  apa: 'Polshyn, H., Budakian, R., &#38; Gu, G. (2013). Cantilever micro-susceptometry
    of mesoscopic Bi2212 samples. In <i>APS March Meeting 2013</i> (Vol. 58). Baltimore,
    MD, United States: American Physical Society.'
  chicago: Polshyn, Hryhoriy, Raffi Budakian, and Genda Gu. “Cantilever Micro-Susceptometry
    of Mesoscopic Bi2212 Samples.” In <i>APS March Meeting 2013</i>, Vol. 58. American
    Physical Society, 2013.
  ieee: H. Polshyn, R. Budakian, and G. Gu, “Cantilever micro-susceptometry of mesoscopic
    Bi2212 samples,” in <i>APS March Meeting 2013</i>, Baltimore, MD, United States,
    2013, vol. 58, no. 1.
  ista: 'Polshyn H, Budakian R, Gu G. 2013. Cantilever micro-susceptometry of mesoscopic
    Bi2212 samples. APS March Meeting 2013. APS: American Physical Society, Bulletin
    of the American Physical Society, vol. 58, N36.00001.'
  mla: Polshyn, Hryhoriy, et al. “Cantilever Micro-Susceptometry of Mesoscopic Bi2212
    Samples.” <i>APS March Meeting 2013</i>, vol. 58, no. 1, N36.00001, American Physical
    Society, 2013.
  short: H. Polshyn, R. Budakian, G. Gu, in:, APS March Meeting 2013, American Physical
    Society, 2013.
conference:
  end_date: 2013-03-22
  location: Baltimore, MD, United States
  name: 'APS: American Physical Society'
  start_date: 2013-03-18
date_created: 2022-02-08T10:34:29Z
date_published: 2013-03-01T00:00:00Z
date_updated: 2022-02-08T10:48:06Z
day: '01'
extern: '1'
intvolume: '        58'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://meetings.aps.org/Meeting/MAR13/Event/186873
month: '03'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2013
publication_identifier:
  issn:
  - 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Cantilever micro-susceptometry of mesoscopic Bi2212 samples
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 58
year: '2013'
...
---
_id: '10750'
abstract:
- lang: eng
  text: The goal of this work is to study the superconducting coherence length in
    the fluctuation regime in cuprate superconductors. In this work we present cantilever
    torque magnetometry measurements of micron-size BSCCO flakes patterned with arrays
    of nanometer scale rings or holes. Using ultrasensitive dynamic torque magnetometry,
    oscillations in magnetization are observed near Tc as a function of the applied
    magnetic flux threading the array. Special effort was made to detect the oscillations
    in magnetization at temperatures above Tc, where the Nernst effect and magnetization
    measurements suggest the possibility of pairing. To constrain the magnitude of
    the coherence length in the fluctuation regime, we will present the dependence
    of the amplitude of the h/2e period oscillations as a function of temperature
    and hole size.
acknowledgement: This work was supported by the Center for Emergent Superconductivity,
  an Energy Frontier Research Center funded by the U.S. DOE, Office of Science, under
  Award No. DE-AC0298CH1088.
alternative_title:
- Bulletin of the American Physical Society
article_number: X21.00008
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: Raffi
  full_name: Budakian, Raffi
  last_name: Budakian
citation:
  ama: 'Polshyn H, Budakian R. Cantilever torque magnetometry study of multiply connected
    BSCCO arrays near Tc. In: <i>APS March Meeting 2012</i>. Vol 57. American Physical
    Society; 2012.'
  apa: 'Polshyn, H., &#38; Budakian, R. (2012). Cantilever torque magnetometry study
    of multiply connected BSCCO arrays near Tc. In <i>APS March Meeting 2012</i> (Vol.
    57). Boston, MA, United States: American Physical Society.'
  chicago: Polshyn, Hryhoriy, and Raffi Budakian. “Cantilever Torque Magnetometry
    Study of Multiply Connected BSCCO Arrays near Tc.” In <i>APS March Meeting 2012</i>,
    Vol. 57. American Physical Society, 2012.
  ieee: H. Polshyn and R. Budakian, “Cantilever torque magnetometry study of multiply
    connected BSCCO arrays near Tc,” in <i>APS March Meeting 2012</i>, Boston, MA,
    United States, 2012, vol. 57, no. 1.
  ista: 'Polshyn H, Budakian R. 2012. Cantilever torque magnetometry study of multiply
    connected BSCCO arrays near Tc. APS March Meeting 2012. APS: American Physical
    Society, Bulletin of the American Physical Society, vol. 57, X21.00008.'
  mla: Polshyn, Hryhoriy, and Raffi Budakian. “Cantilever Torque Magnetometry Study
    of Multiply Connected BSCCO Arrays near Tc.” <i>APS March Meeting 2012</i>, vol.
    57, no. 1, X21.00008, American Physical Society, 2012.
  short: H. Polshyn, R. Budakian, in:, APS March Meeting 2012, American Physical Society,
    2012.
conference:
  end_date: 2012-03-02
  location: Boston, MA, United States
  name: 'APS: American Physical Society'
  start_date: 2012-02-27
date_created: 2022-02-08T10:39:08Z
date_published: 2012-02-01T00:00:00Z
date_updated: 2022-02-08T10:48:01Z
day: '01'
extern: '1'
intvolume: '        57'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://meetings.aps.org/Meeting/MAR12/Event/167014
month: '02'
oa: 1
oa_version: Published Version
publication: APS March Meeting 2012
publication_identifier:
  issn:
  - 0003-0503
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Cantilever torque magnetometry study of multiply connected BSCCO arrays near
  Tc
type: conference
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 57
year: '2012'
...