[{"ddc":["530"],"volume":128,"acknowledgement":"This research was supported by the Scientific Service Units of ISTA through resources provided by the MIBA Machine Shop and the nanofabrication facility. This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie\r\nSkłodowska-Curie Grant Agreement No. 844511, No. 75441, and by the FWF-P 30207, I05060, and M3032-N projects. A. B. acknowledges support from the EU Horizon-2020 FET project microSPIRE, ID: 766955. P.M. M. and G. B. acknowledge funding by the Deutsche Forschungsgemeinschaft (DFG—German Research Foundation) under Project No. 450396347. This work was supported by the Royal Society (URF\\R1\\191150) and the European Research Council (Grant Agreement No. 948932), N. A. acknowledges the use of the University of Oxford Advanced Research Computing (ARC) facility.","isi":1,"external_id":{"arxiv":["2111.05130"],"isi":["000786542500004"]},"date_updated":"2023-08-03T06:14:58Z","citation":{"mla":"Jirovec, Daniel, et al. “Dynamics of Hole Singlet-Triplet Qubits with Large g-Factor Differences.” <i>Physical Review Letters</i>, vol. 128, no. 12, 126803, American Physical Society, 2022, doi:<a href=\"https://doi.org/10.1103/PhysRevLett.128.126803\">10.1103/PhysRevLett.128.126803</a>.","short":"D. Jirovec, P.M. Mutter, A.C. Hofmann, A. Crippa, M. Rychetsky, D.L. Craig, J. Kukucka, F. Martins, A. Ballabio, N. Ares, D. Chrastina, G. Isella, G. Burkard, G. Katsaros, Physical Review Letters 128 (2022).","ista":"Jirovec D, Mutter PM, Hofmann AC, Crippa A, Rychetsky M, Craig DL, Kukucka J, Martins F, Ballabio A, Ares N, Chrastina D, Isella G, Burkard G, Katsaros G. 2022. Dynamics of hole singlet-triplet qubits with large g-factor differences. Physical Review Letters. 128(12), 126803.","ama":"Jirovec D, Mutter PM, Hofmann AC, et al. Dynamics of hole singlet-triplet qubits with large g-factor differences. <i>Physical Review Letters</i>. 2022;128(12). doi:<a href=\"https://doi.org/10.1103/PhysRevLett.128.126803\">10.1103/PhysRevLett.128.126803</a>","apa":"Jirovec, D., Mutter, P. M., Hofmann, A. C., Crippa, A., Rychetsky, M., Craig, D. L., … Katsaros, G. (2022). Dynamics of hole singlet-triplet qubits with large g-factor differences. <i>Physical Review Letters</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevLett.128.126803\">https://doi.org/10.1103/PhysRevLett.128.126803</a>","ieee":"D. Jirovec <i>et al.</i>, “Dynamics of hole singlet-triplet qubits with large g-factor differences,” <i>Physical Review Letters</i>, vol. 128, no. 12. American Physical Society, 2022.","chicago":"Jirovec, Daniel, Philipp M. Mutter, Andrea C Hofmann, Alessandro Crippa, Marek Rychetsky, David L. Craig, Josip Kukucka, et al. “Dynamics of Hole Singlet-Triplet Qubits with Large g-Factor Differences.” <i>Physical Review Letters</i>. American Physical Society, 2022. <a href=\"https://doi.org/10.1103/PhysRevLett.128.126803\">https://doi.org/10.1103/PhysRevLett.128.126803</a>."},"year":"2022","abstract":[{"text":"The spin-orbit interaction permits to control the state of a spin qubit via electric fields. For holes it is particularly strong, allowing for fast all electrical qubit manipulation, and yet an in-depth understanding of this interaction in hole systems is missing. Here we investigate, experimentally and theoretically, the effect of the cubic Rashba spin-orbit interaction on the mixing of the spin states by studying singlet-triplet oscillations in a planar Ge hole double quantum dot. Landau-Zener sweeps at different magnetic field directions allow us to disentangle the effects of the spin-orbit induced spin-flip term from those caused by strongly site-dependent and anisotropic quantum dot g tensors. Our work, therefore, provides new insights into the hole spin-orbit interaction, necessary for optimizing future qubit experiments.","lang":"eng"}],"doi":"10.1103/PhysRevLett.128.126803","arxiv":1,"day":"24","file_date_updated":"2022-03-28T06:53:39Z","ec_funded":1,"quality_controlled":"1","article_type":"original","publisher":"American Physical Society","author":[{"last_name":"Jirovec","first_name":"Daniel","full_name":"Jirovec, Daniel","orcid":"0000-0002-7197-4801","id":"4C473F58-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Philipp M.","last_name":"Mutter","full_name":"Mutter, Philipp M."},{"last_name":"Hofmann","first_name":"Andrea C","full_name":"Hofmann, Andrea C","id":"340F461A-F248-11E8-B48F-1D18A9856A87"},{"id":"1F2B21A2-F6E7-11E9-9B82-F7DBE5697425","last_name":"Crippa","first_name":"Alessandro","full_name":"Crippa, Alessandro","orcid":"0000-0002-2968-611X"},{"last_name":"Rychetsky","first_name":"Marek","full_name":"Rychetsky, Marek"},{"first_name":"David L.","last_name":"Craig","full_name":"Craig, David L."},{"id":"3F5D8856-F248-11E8-B48F-1D18A9856A87","last_name":"Kukucka","first_name":"Josip","full_name":"Kukucka, Josip"},{"first_name":"Frederico","last_name":"Martins","orcid":"0000-0003-2668-2401","full_name":"Martins, Frederico","id":"38F80F9A-1CB8-11EA-BC76-B49B3DDC885E"},{"last_name":"Ballabio","first_name":"Andrea","full_name":"Ballabio, Andrea"},{"first_name":"Natalia","last_name":"Ares","full_name":"Ares, Natalia"},{"full_name":"Chrastina, Daniel","first_name":"Daniel","last_name":"Chrastina"},{"full_name":"Isella, Giovanni","last_name":"Isella","first_name":"Giovanni"},{"last_name":"Burkard","first_name":"Guido ","full_name":"Burkard, Guido "},{"id":"38DB5788-F248-11E8-B48F-1D18A9856A87","full_name":"Katsaros, Georgios","first_name":"Georgios","last_name":"Katsaros"}],"issue":"12","_id":"10920","title":"Dynamics of hole singlet-triplet qubits with large g-factor differences","intvolume":"       128","publication_status":"published","article_processing_charge":"No","date_created":"2022-03-24T15:51:11Z","department":[{"_id":"GradSch"},{"_id":"GeKa"}],"status":"public","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","file":[{"file_name":"2022_PhysRevLetters_Jirovec.pdf","content_type":"application/pdf","date_updated":"2022-03-28T06:53:39Z","file_size":1266515,"checksum":"6e66ad548d18db9c131f304acbd5a1f4","date_created":"2022-03-28T06:53:39Z","creator":"dernst","file_id":"10928","success":1,"access_level":"open_access","relation":"main_file"}],"date_published":"2022-03-24T00:00:00Z","type":"journal_article","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"oa":1,"publication_identifier":{"eissn":["1079-7114"]},"language":[{"iso":"eng"}],"publication":"Physical Review Letters","has_accepted_license":"1","month":"03","article_number":"126803","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"oa_version":"Published Version","project":[{"grant_number":"844511","name":"Majorana bound states in Ge/SiGe heterostructures","call_identifier":"H2020","_id":"26A151DA-B435-11E9-9278-68D0E5697425"},{"grant_number":"754411","name":"ISTplus - Postdoctoral Fellowships","_id":"260C2330-B435-11E9-9278-68D0E5697425","call_identifier":"H2020"},{"grant_number":"P30207","name":"Hole spin orbit qubits in Ge quantum wells","call_identifier":"FWF","_id":"2641CE5E-B435-11E9-9278-68D0E5697425"},{"name":"High impedance circuit quantum electrodynamics with hole spins","grant_number":"I05060","_id":"c0977eea-5a5b-11eb-8a69-a862db0cf4d1"},{"grant_number":"M03032","name":"Long-range spin exchange for 2D qubits architectures","_id":"c08c05c4-5a5b-11eb-8a69-dc6ce49d7973"}]},{"related_material":{"record":[{"status":"public","relation":"research_data","id":"9323"},{"status":"public","id":"10058","relation":"dissertation_contains"}],"link":[{"url":"https://ist.ac.at/en/news/quantum-computing-with-holes/","relation":"press_release","description":"News on IST Homepage"}]},"status":"public","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/2011.13755"}],"type":"journal_article","date_published":"2021-08-01T00:00:00Z","oa":1,"publication_identifier":{"eissn":["1476-4660"],"issn":["1476-1122"]},"language":[{"iso":"eng"}],"publication":"Nature Materials","month":"08","project":[{"name":"Majorana bound states in Ge/SiGe heterostructures","grant_number":"844511","call_identifier":"H2020","_id":"26A151DA-B435-11E9-9278-68D0E5697425"},{"call_identifier":"H2020","_id":"260C2330-B435-11E9-9278-68D0E5697425","grant_number":"754411","name":"ISTplus - Postdoctoral Fellowships"},{"grant_number":"P30207","name":"Hole spin orbit qubits in Ge quantum wells","call_identifier":"FWF","_id":"2641CE5E-B435-11E9-9278-68D0E5697425"},{"name":"Hybrid Semiconductor - Superconductor Quantum Devices","_id":"262116AA-B435-11E9-9278-68D0E5697425"}],"oa_version":"Preprint","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"acknowledgement":"This research was supported by the Scientific Service Units of Institute of Science and Technology (IST) Austria through resources provided by the Miba Machine Shop and the nanofabrication facility, and was made possible with the support of the NOMIS Foundation. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreements no. 844511 and no. 75441, and by the Austrian Science Fund FWF-P 30207 project. A.B. acknowledges support from the European Union Horizon 2020 FET project microSPIRE, no. 766955. M. Botifoll and J.A. acknowledge funding from Generalitat de Catalunya 2017 SGR 327. The Catalan Institute of Nanoscience and Nanotechnology (ICN2) is supported by the Severo Ochoa programme from the Spanish Ministery of Economy (MINECO) (grant no. SEV-2017-0706) and is funded by the Catalonian Research Centre (CERCA) Programme, Generalitat de Catalunya. Part of the present work has been performed within the framework of the Universitat Autónoma de Barcelona Materials Science PhD programme. Part of the HAADF scanning transmission electron microscopy was conducted in the Laboratorio de Microscopias Avanzadas at Instituto de Nanociencia de Aragon, Universidad de Zaragoza. ICN2 acknowledge support from the Spanish Superior Council of Scientific Research (CSIC) Research Platform on Quantum Technologies PTI-001. M.B. acknowledges funding from the Catalan Agency for Management of University and Research Grants (AGAUR) Generalitat de Catalunya formation of investigators (FI) PhD grant.","volume":20,"external_id":{"arxiv":["2011.13755"],"isi":["000657596400001"]},"isi":1,"citation":{"ieee":"D. Jirovec <i>et al.</i>, “A singlet triplet hole spin qubit in planar Ge,” <i>Nature Materials</i>, vol. 20, no. 8. Springer Nature, pp. 1106–1112, 2021.","chicago":"Jirovec, Daniel, Andrea C Hofmann, Andrea Ballabio, Philipp M. Mutter, Giulio Tavani, Marc Botifoll, Alessandro Crippa, et al. “A Singlet Triplet Hole Spin Qubit in Planar Ge.” <i>Nature Materials</i>. Springer Nature, 2021. <a href=\"https://doi.org/10.1038/s41563-021-01022-2\">https://doi.org/10.1038/s41563-021-01022-2</a>.","ama":"Jirovec D, Hofmann AC, Ballabio A, et al. A singlet triplet hole spin qubit in planar Ge. <i>Nature Materials</i>. 2021;20(8):1106–1112. doi:<a href=\"https://doi.org/10.1038/s41563-021-01022-2\">10.1038/s41563-021-01022-2</a>","apa":"Jirovec, D., Hofmann, A. C., Ballabio, A., Mutter, P. M., Tavani, G., Botifoll, M., … Katsaros, G. (2021). A singlet triplet hole spin qubit in planar Ge. <i>Nature Materials</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41563-021-01022-2\">https://doi.org/10.1038/s41563-021-01022-2</a>","ista":"Jirovec D, Hofmann AC, Ballabio A, Mutter PM, Tavani G, Botifoll M, Crippa A, Kukucka J, Sagi O, Martins F, Saez Mollejo J, Prieto Gonzalez I, Borovkov M, Arbiol J, Chrastina D, Isella G, Katsaros G. 2021. A singlet triplet hole spin qubit in planar Ge. Nature Materials. 20(8), 1106–1112.","short":"D. Jirovec, A.C. Hofmann, A. Ballabio, P.M. Mutter, G. Tavani, M. Botifoll, A. Crippa, J. Kukucka, O. Sagi, F. Martins, J. Saez Mollejo, I. Prieto Gonzalez, M. Borovkov, J. Arbiol, D. Chrastina, G. Isella, G. Katsaros, Nature Materials 20 (2021) 1106–1112.","mla":"Jirovec, Daniel, et al. “A Singlet Triplet Hole Spin Qubit in Planar Ge.” <i>Nature Materials</i>, vol. 20, no. 8, Springer Nature, 2021, pp. 1106–1112, doi:<a href=\"https://doi.org/10.1038/s41563-021-01022-2\">10.1038/s41563-021-01022-2</a>."},"year":"2021","date_updated":"2024-03-25T23:30:14Z","abstract":[{"text":"Spin qubits are considered to be among the most promising candidates for building a quantum processor. Group IV hole spin qubits have moved into the focus of interest due to the ease of operation and compatibility with Si technology. In addition, Ge offers the option for monolithic superconductor-semiconductor integration. Here we demonstrate a hole spin qubit operating at fields below 10 mT, the critical field of Al, by exploiting the large out-of-plane hole g-factors in planar Ge and by encoding the qubit into the singlet-triplet states of a double quantum dot. We observe electrically controlled X and Z-rotations with tunable frequencies exceeding 100 MHz and dephasing times of 1μs which we extend beyond 15μs with echo techniques. These results show that Ge hole singlet triplet qubits outperform their electronic Si and GaAs based counterparts in speed and coherence, respectively. In addition, they are on par with Ge single spin qubits, but can be operated at much lower fields underlining their potential for on chip integration with superconducting technologies.","lang":"eng"}],"day":"01","doi":"10.1038/s41563-021-01022-2","arxiv":1,"quality_controlled":"1","ec_funded":1,"page":"1106–1112","article_type":"original","publisher":"Springer Nature","issue":"8","author":[{"id":"4C473F58-F248-11E8-B48F-1D18A9856A87","last_name":"Jirovec","first_name":"Daniel","full_name":"Jirovec, Daniel","orcid":"0000-0002-7197-4801"},{"last_name":"Hofmann","first_name":"Andrea C","full_name":"Hofmann, Andrea C","id":"340F461A-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Andrea","last_name":"Ballabio","full_name":"Ballabio, Andrea"},{"full_name":"Mutter, Philipp M.","first_name":"Philipp M.","last_name":"Mutter"},{"full_name":"Tavani, Giulio","last_name":"Tavani","first_name":"Giulio"},{"full_name":"Botifoll, Marc","last_name":"Botifoll","first_name":"Marc"},{"id":"1F2B21A2-F6E7-11E9-9B82-F7DBE5697425","last_name":"Crippa","first_name":"Alessandro","full_name":"Crippa, Alessandro","orcid":"0000-0002-2968-611X"},{"id":"3F5D8856-F248-11E8-B48F-1D18A9856A87","last_name":"Kukucka","first_name":"Josip","full_name":"Kukucka, Josip"},{"last_name":"Sagi","first_name":"Oliver","full_name":"Sagi, Oliver","id":"71616374-A8E9-11E9-A7CA-09ECE5697425"},{"orcid":"0000-0003-2668-2401","full_name":"Martins, Frederico","first_name":"Frederico","last_name":"Martins","id":"38F80F9A-1CB8-11EA-BC76-B49B3DDC885E"},{"id":"e0390f72-f6e0-11ea-865d-862393336714","last_name":"Saez Mollejo","first_name":"Jaime","full_name":"Saez Mollejo, Jaime"},{"orcid":"0000-0002-7370-5357","full_name":"Prieto Gonzalez, Ivan","first_name":"Ivan","last_name":"Prieto Gonzalez","id":"2A307FE2-F248-11E8-B48F-1D18A9856A87"},{"id":"2ac7a0a2-3562-11eb-9256-fbd18ea55087","last_name":"Borovkov","first_name":"Maksim","full_name":"Borovkov, Maksim"},{"last_name":"Arbiol","first_name":"Jordi","full_name":"Arbiol, Jordi"},{"full_name":"Chrastina, Daniel","last_name":"Chrastina","first_name":"Daniel"},{"full_name":"Isella, Giovanni","last_name":"Isella","first_name":"Giovanni"},{"id":"38DB5788-F248-11E8-B48F-1D18A9856A87","last_name":"Katsaros","first_name":"Georgios","full_name":"Katsaros, Georgios","orcid":"0000-0001-8342-202X"}],"scopus_import":"1","_id":"8909","intvolume":"        20","title":"A singlet triplet hole spin qubit in planar Ge","article_processing_charge":"No","department":[{"_id":"GeKa"},{"_id":"NanoFab"},{"_id":"GradSch"}],"date_created":"2020-12-02T10:50:47Z","publication_status":"published"},{"volume":6,"acknowledgement":"G.S., M.W.,F.A.Z acknowledge financial support from The Netherlands Organization for Scientific Research (NWO). F.Z., D.L., G.K. acknowledge funding from the European Union’s Horizon 2020 research and innovation programme under Grand Agreement Nr. 862046. G.K. acknowledges funding from FP7 ERC Starting Grant 335497, FWF Y 715-N30, FWF P-30207. S.D. acknowledges support from the European Union’s Horizon 2020 program under Grant\r\nAgreement No. 81050 and from the Agence Nationale de la Recherche through the TOPONANO and CMOSQSPIN projects. J.Z. acknowledges support from the National Key R&D Program of China (Grant No. 2016YFA0301701) and Strategic Priority Research Program of CAS (Grant No. XDB30000000). D.L. and C.K. acknowledge the Swiss National Science Foundation and NCCR QSIT.","arxiv":1,"doi":"10.1038/s41578-020-00262-z","day":"01","abstract":[{"text":"In the worldwide endeavor for disruptive quantum technologies, germanium is emerging as a versatile material to realize devices capable of encoding, processing, or transmitting quantum information. These devices leverage special properties of the germanium valence-band states, commonly known as holes, such as their inherently strong spin-orbit coupling and the ability to host superconducting pairing correlations. In this Review, we initially introduce the physics of holes in low-dimensional germanium structures with key insights from a theoretical perspective. We then examine the material science progress underpinning germanium-based planar heterostructures and nanowires. We review the most significant experimental results demonstrating key building blocks for quantum technology, such as an electrically driven universal quantum gate set with spin qubits in quantum dots and superconductor-semiconductor devices for hybrid quantum systems. We conclude by identifying the most promising prospects\r\ntoward scalable quantum information processing. ","lang":"eng"}],"date_updated":"2024-03-07T14:48:57Z","citation":{"short":"G. Scappucci, C. Kloeffel, F.A. Zwanenburg, D. Loss, M. Myronov, J.-J. Zhang, S.D. Franceschi, G. Katsaros, M. Veldhorst, Nature Reviews Materials 6 (2021) 926–943.","mla":"Scappucci, Giordano, et al. “The Germanium Quantum Information Route.” <i>Nature Reviews Materials</i>, vol. 6, Springer Nature, 2021, pp. 926–943, doi:<a href=\"https://doi.org/10.1038/s41578-020-00262-z\">10.1038/s41578-020-00262-z</a>.","ista":"Scappucci G, Kloeffel C, Zwanenburg FA, Loss D, Myronov M, Zhang J-J, Franceschi SD, Katsaros G, Veldhorst M. 2021. The germanium quantum information route. Nature Reviews Materials. 6, 926–943.","apa":"Scappucci, G., Kloeffel, C., Zwanenburg, F. A., Loss, D., Myronov, M., Zhang, J.-J., … Veldhorst, M. (2021). The germanium quantum information route. <i>Nature Reviews Materials</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41578-020-00262-z\">https://doi.org/10.1038/s41578-020-00262-z</a>","ama":"Scappucci G, Kloeffel C, Zwanenburg FA, et al. The germanium quantum information route. <i>Nature Reviews Materials</i>. 2021;6:926–943. doi:<a href=\"https://doi.org/10.1038/s41578-020-00262-z\">10.1038/s41578-020-00262-z</a>","ieee":"G. Scappucci <i>et al.</i>, “The germanium quantum information route,” <i>Nature Reviews Materials</i>, vol. 6. Springer Nature, pp. 926–943, 2021.","chicago":"Scappucci, Giordano, Christoph Kloeffel, Floris A. Zwanenburg, Daniel Loss, Maksym Myronov, Jian-Jun Zhang, Silvano De Franceschi, Georgios Katsaros, and Menno Veldhorst. “The Germanium Quantum Information Route.” <i>Nature Reviews Materials</i>. Springer Nature, 2021. <a href=\"https://doi.org/10.1038/s41578-020-00262-z\">https://doi.org/10.1038/s41578-020-00262-z</a>."},"year":"2021","isi":1,"external_id":{"isi":["000600826100003"],"arxiv":["2004.08133"]},"publisher":"Springer Nature","article_type":"original","page":"926–943 ","ec_funded":1,"quality_controlled":"1","publication_status":"published","department":[{"_id":"GeKa"}],"date_created":"2020-12-02T10:52:51Z","article_processing_charge":"No","title":"The germanium quantum information route","intvolume":"         6","_id":"8911","scopus_import":"1","author":[{"last_name":"Scappucci","first_name":"Giordano","full_name":"Scappucci, Giordano"},{"full_name":"Kloeffel, Christoph","last_name":"Kloeffel","first_name":"Christoph"},{"last_name":"Zwanenburg","first_name":"Floris A.","full_name":"Zwanenburg, Floris A."},{"last_name":"Loss","first_name":"Daniel","full_name":"Loss, Daniel"},{"first_name":"Maksym","last_name":"Myronov","full_name":"Myronov, Maksym"},{"full_name":"Zhang, Jian-Jun","first_name":"Jian-Jun","last_name":"Zhang"},{"full_name":"Franceschi, Silvano De","last_name":"Franceschi","first_name":"Silvano De"},{"id":"38DB5788-F248-11E8-B48F-1D18A9856A87","first_name":"Georgios","last_name":"Katsaros","orcid":"0000-0001-8342-202X","full_name":"Katsaros, Georgios"},{"full_name":"Veldhorst, Menno","first_name":"Menno","last_name":"Veldhorst"}],"main_file_link":[{"url":"https://arxiv.org/abs/2004.08133","open_access":"1"}],"user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","status":"public","publication_identifier":{"eissn":["2058-8437"]},"oa":1,"date_published":"2021-10-01T00:00:00Z","type":"journal_article","language":[{"iso":"eng"}],"oa_version":"Preprint","project":[{"name":"Towards Spin qubits and Majorana fermions in Germanium selfassembled hut-wires","grant_number":"335497","call_identifier":"FP7","_id":"25517E86-B435-11E9-9278-68D0E5697425"},{"_id":"2552F888-B435-11E9-9278-68D0E5697425","call_identifier":"FWF","grant_number":"Y00715","name":"Loch Spin-Qubits und Majorana-Fermionen in Germanium"},{"name":"Hole spin orbit qubits in Ge quantum wells","grant_number":"P30207","call_identifier":"FWF","_id":"2641CE5E-B435-11E9-9278-68D0E5697425"}],"month":"10","publication":"Nature Reviews Materials"},{"page":"151","file_date_updated":"2022-12-20T23:30:07Z","publisher":"Institute of Science and Technology Austria","_id":"10058","author":[{"id":"4C473F58-F248-11E8-B48F-1D18A9856A87","first_name":"Daniel","last_name":"Jirovec","orcid":"0000-0002-7197-4801","full_name":"Jirovec, Daniel"}],"department":[{"_id":"GradSch"},{"_id":"GeKa"}],"date_created":"2021-09-30T07:53:49Z","article_processing_charge":"No","publication_status":"published","alternative_title":["ISTA Thesis"],"title":"Singlet-Triplet qubits and spin-orbit interaction in 2-dimensional Ge hole gases","acknowledgement":"The author gratefully acknowledges support by the Austrian Science Fund (FWF), grants No P30207, and the Nomis foundation.","ddc":["621","539"],"year":"2021","citation":{"mla":"Jirovec, Daniel. <i>Singlet-Triplet Qubits and Spin-Orbit Interaction in 2-Dimensional Ge Hole Gases</i>. Institute of Science and Technology Austria, 2021, doi:<a href=\"https://doi.org/10.15479/at:ista:10058\">10.15479/at:ista:10058</a>.","short":"D. Jirovec, Singlet-Triplet Qubits and Spin-Orbit Interaction in 2-Dimensional Ge Hole Gases, Institute of Science and Technology Austria, 2021.","ista":"Jirovec D. 2021. Singlet-Triplet qubits and spin-orbit interaction in 2-dimensional Ge hole gases. Institute of Science and Technology Austria.","ama":"Jirovec D. Singlet-Triplet qubits and spin-orbit interaction in 2-dimensional Ge hole gases. 2021. doi:<a href=\"https://doi.org/10.15479/at:ista:10058\">10.15479/at:ista:10058</a>","apa":"Jirovec, D. (2021). <i>Singlet-Triplet qubits and spin-orbit interaction in 2-dimensional Ge hole gases</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:10058\">https://doi.org/10.15479/at:ista:10058</a>","chicago":"Jirovec, Daniel. “Singlet-Triplet Qubits and Spin-Orbit Interaction in 2-Dimensional Ge Hole Gases.” Institute of Science and Technology Austria, 2021. <a href=\"https://doi.org/10.15479/at:ista:10058\">https://doi.org/10.15479/at:ista:10058</a>.","ieee":"D. Jirovec, “Singlet-Triplet qubits and spin-orbit interaction in 2-dimensional Ge hole gases,” Institute of Science and Technology Austria, 2021."},"date_updated":"2023-09-08T11:41:08Z","day":"05","doi":"10.15479/at:ista:10058","degree_awarded":"PhD","abstract":[{"lang":"eng","text":"Quantum information and computation has become a vast field paved with opportunities for researchers and investors. As large multinational companies and international funds are heavily investing in quantum technologies it is still a question which platform is best suited for the task of realizing a scalable quantum processor. In this work we investigate hole spins in Ge quantum wells. These hold great promise as they possess several favorable properties: a small effective mass, a strong spin-orbit coupling, long relaxation time and an inherent immunity to hyperfine noise. All these characteristics helped Ge hole spin qubits to evolve from a single qubit to a fully entangled four qubit processor in only 3 years. Here, we investigated a qubit approach leveraging the large out-of-plane g-factors of heavy hole states in Ge quantum dots. We found this qubit to be reproducibly operable at extremely low magnetic field and at large speeds while maintaining coherence. This was possible because large differences of g-factors in adjacent dots can be achieved in the out-of-plane direction. In the in-plane direction the small g-factors, on the other hand, can be altered very effectively by the confinement potentials. Here, we found that this can even lead to a sign change of the g-factors. The resulting g-factor difference alters the dynamics of the system drastically and produces effects typically attributed to a spin-orbit induced spin-flip term.  The investigations carried out in this thesis give further insights into the possibilities of holes in Ge and reveal new physical properties that need to be considered when designing future spin qubit experiments."}],"keyword":["qubits","quantum computing","holes"],"language":[{"iso":"eng"}],"has_accepted_license":"1","project":[{"name":"Hole spin orbit qubits in Ge quantum wells","grant_number":"P30207","_id":"2641CE5E-B435-11E9-9278-68D0E5697425","call_identifier":"FWF"}],"oa_version":"Published Version","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"month":"10","file":[{"date_created":"2021-09-30T14:29:14Z","embargo_to":"open_access","checksum":"ad6bcb24083ed7c02baaf1885c9ea3d5","file_size":32397600,"date_updated":"2022-12-20T23:30:07Z","file_name":"PHD_Thesis_Jirovec_Source.zip","content_type":"application/x-zip-compressed","relation":"source_file","access_level":"closed","file_id":"10061","creator":"djirovec"},{"date_created":"2021-10-05T07:56:49Z","embargo":"2022-10-06","file_size":26910829,"checksum":"5fbe08d4f66d1153e04c47971538fae8","date_updated":"2022-12-20T23:30:07Z","file_name":"PHD_Thesis_pdfa2b_1.pdf","content_type":"application/pdf","relation":"main_file","access_level":"open_access","file_id":"10087","creator":"djirovec"}],"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","related_material":{"record":[{"status":"public","relation":"part_of_dissertation","id":"8831"},{"status":"public","relation":"part_of_dissertation","id":"10065"},{"id":"10066","relation":"part_of_dissertation","status":"public"},{"status":"public","id":"8909","relation":"part_of_dissertation"},{"id":"5816","relation":"part_of_dissertation","status":"public"}]},"status":"public","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"type":"dissertation","date_published":"2021-10-05T00:00:00Z","publication_identifier":{"issn":["2663-337X"]},"oa":1,"supervisor":[{"id":"38DB5788-F248-11E8-B48F-1D18A9856A87","full_name":"Katsaros, Georgios","orcid":"0000-0001-8342-202X","last_name":"Katsaros","first_name":"Georgios"}]},{"date_published":"2021-07-27T00:00:00Z","type":"preprint","external_id":{"arxiv":["2107.12975"]},"date_updated":"2024-03-25T23:30:14Z","citation":{"chicago":"Severin, B., D. T. Lennon, L. C. Camenzind, F. Vigneau, F. Fedele, Daniel Jirovec, A. Ballabio, et al. “Cross-Architecture Tuning of Silicon and SiGe-Based Quantum Devices Using Machine Learning.” <i>ArXiv</i>, n.d. <a href=\"https://doi.org/10.48550/arXiv.2107.12975\">https://doi.org/10.48550/arXiv.2107.12975</a>.","ieee":"B. Severin <i>et al.</i>, “Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning,” <i>arXiv</i>. .","ama":"Severin B, Lennon DT, Camenzind LC, et al. Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning. <i>arXiv</i>. doi:<a href=\"https://doi.org/10.48550/arXiv.2107.12975\">10.48550/arXiv.2107.12975</a>","apa":"Severin, B., Lennon, D. T., Camenzind, L. C., Vigneau, F., Fedele, F., Jirovec, D., … Ares, N. (n.d.). Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning. <i>arXiv</i>. <a href=\"https://doi.org/10.48550/arXiv.2107.12975\">https://doi.org/10.48550/arXiv.2107.12975</a>","ista":"Severin B, Lennon DT, Camenzind LC, Vigneau F, Fedele F, Jirovec D, Ballabio A, Chrastina D, Isella G, Kruijf M de, Carballido MJ, Svab S, Kuhlmann AV, Braakman FR, Geyer S, Froning FNM, Moon H, Osborne MA, Sejdinovic D, Katsaros G, Zumbühl DM, Briggs GAD, Ares N. Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning. arXiv, 2107.12975.","mla":"Severin, B., et al. “Cross-Architecture Tuning of Silicon and SiGe-Based Quantum Devices Using Machine Learning.” <i>ArXiv</i>, 2107.12975, doi:<a href=\"https://doi.org/10.48550/arXiv.2107.12975\">10.48550/arXiv.2107.12975</a>.","short":"B. Severin, D.T. Lennon, L.C. Camenzind, F. Vigneau, F. Fedele, D. Jirovec, A. Ballabio, D. Chrastina, G. Isella, M. de Kruijf, M.J. Carballido, S. Svab, A.V. Kuhlmann, F.R. Braakman, S. Geyer, F.N.M. Froning, H. Moon, M.A. Osborne, D. Sejdinovic, G. Katsaros, D.M. Zumbühl, G.A.D. Briggs, N. Ares, ArXiv (n.d.)."},"year":"2021","abstract":[{"text":"The potential of Si and SiGe-based devices for the scaling of quantum circuits is tainted by device variability. Each device needs to be tuned to operation conditions. We give a key step towards tackling this variability with an algorithm that, without modification, is capable of tuning a 4-gate Si FinFET, a 5-gate GeSi nanowire and a 7-gate SiGe heterostructure double quantum dot device from scratch. We achieve tuning times of 30, 10, and 92 minutes, respectively. The algorithm also provides insight into the parameter space landscape for each of these devices. These results show that overarching solutions for the tuning of quantum devices are enabled by machine learning.","lang":"eng"}],"oa":1,"doi":"10.48550/arXiv.2107.12975","arxiv":1,"day":"27","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","status":"public","related_material":{"record":[{"status":"public","relation":"dissertation_contains","id":"10058"}]},"acknowledgement":"We acknowledge Ang Li, Erik P. A. M. Bakkers (University of Eindhoven) for the fabrication of the Ge/Si nanowire. This work was supported by the Royal Society, the EPSRC National Quantum Technology Hub in Networked Quantum Information Technology (EP/M013243/1), Quantum Technology Capital (EP/N014995/1), EPSRC Platform Grant\r\n(EP/R029229/1), the European Research Council (Grant agreement 948932), the Swiss Nanoscience Institute, the\r\nNCCR SPIN, the EU H2020 European Microkelvin Platform EMP grant No. 824109, the Scientific Service Units\r\nof IST Austria through resources provided by the nanofabrication facility and, the FWF-P30207 project. This publication was also made possible through support from Templeton World Charity Foundation and John Templeton Foundation. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the Templeton Foundations.","main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.2107.12975"}],"author":[{"full_name":"Severin, B.","last_name":"Severin","first_name":"B."},{"full_name":"Lennon, D. T.","last_name":"Lennon","first_name":"D. T."},{"full_name":"Camenzind, L. C.","first_name":"L. C.","last_name":"Camenzind"},{"first_name":"F.","last_name":"Vigneau","full_name":"Vigneau, F."},{"full_name":"Fedele, F.","last_name":"Fedele","first_name":"F."},{"id":"4C473F58-F248-11E8-B48F-1D18A9856A87","last_name":"Jirovec","first_name":"Daniel","full_name":"Jirovec, Daniel","orcid":"0000-0002-7197-4801"},{"first_name":"A.","last_name":"Ballabio","full_name":"Ballabio, A."},{"last_name":"Chrastina","first_name":"D.","full_name":"Chrastina, D."},{"full_name":"Isella, G.","first_name":"G.","last_name":"Isella"},{"last_name":"Kruijf","first_name":"M. de","full_name":"Kruijf, M. de"},{"first_name":"M. J.","last_name":"Carballido","full_name":"Carballido, M. J."},{"full_name":"Svab, S.","first_name":"S.","last_name":"Svab"},{"last_name":"Kuhlmann","first_name":"A. V.","full_name":"Kuhlmann, A. V."},{"last_name":"Braakman","first_name":"F. R.","full_name":"Braakman, F. R."},{"full_name":"Geyer, S.","last_name":"Geyer","first_name":"S."},{"full_name":"Froning, F. N. M.","last_name":"Froning","first_name":"F. N. M."},{"last_name":"Moon","first_name":"H.","full_name":"Moon, H."},{"first_name":"M. A.","last_name":"Osborne","full_name":"Osborne, M. A."},{"first_name":"D.","last_name":"Sejdinovic","full_name":"Sejdinovic, D."},{"orcid":"0000-0001-8342-202X","full_name":"Katsaros, Georgios","first_name":"Georgios","last_name":"Katsaros","id":"38DB5788-F248-11E8-B48F-1D18A9856A87"},{"full_name":"Zumbühl, D. M.","first_name":"D. M.","last_name":"Zumbühl"},{"full_name":"Briggs, G. A. D.","first_name":"G. A. D.","last_name":"Briggs"},{"first_name":"N.","last_name":"Ares","full_name":"Ares, N."}],"_id":"10066","publication":"arXiv","month":"07","title":"Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning","article_number":"2107.12975","oa_version":"Preprint","acknowledged_ssus":[{"_id":"NanoFab"}],"publication_status":"submitted","date_created":"2021-10-01T12:40:22Z","department":[{"_id":"GeKa"}],"article_processing_charge":"No","project":[{"name":"Hole spin orbit qubits in Ge quantum wells","grant_number":"P30207","call_identifier":"FWF","_id":"2641CE5E-B435-11E9-9278-68D0E5697425"}],"language":[{"iso":"eng"}]},{"oa_version":"Preprint","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"project":[{"call_identifier":"H2020","_id":"26A151DA-B435-11E9-9278-68D0E5697425","grant_number":"844511","name":"Majorana bound states in Ge/SiGe heterostructures"},{"call_identifier":"FWF","_id":"2641CE5E-B435-11E9-9278-68D0E5697425","name":"Hole spin orbit qubits in Ge quantum wells","grant_number":"P30207"}],"month":"10","article_number":"1910.05841","publication":"arXiv","language":[{"iso":"eng"}],"oa":1,"date_published":"2019-10-13T00:00:00Z","type":"preprint","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1910.05841"}],"related_material":{"record":[{"status":"public","relation":"dissertation_contains","id":"10058"}]},"status":"public","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publication_status":"submitted","article_processing_charge":"No","date_created":"2021-10-01T12:14:51Z","department":[{"_id":"GeKa"}],"title":"Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits","_id":"10065","author":[{"first_name":"Andrea C","last_name":"Hofmann","full_name":"Hofmann, Andrea C","id":"340F461A-F248-11E8-B48F-1D18A9856A87"},{"id":"4C473F58-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-7197-4801","full_name":"Jirovec, Daniel","first_name":"Daniel","last_name":"Jirovec"},{"first_name":"Maxim","last_name":"Borovkov","full_name":"Borovkov, Maxim"},{"first_name":"Ivan","last_name":"Prieto Gonzalez","orcid":"0000-0002-7370-5357","full_name":"Prieto Gonzalez, Ivan","id":"2A307FE2-F248-11E8-B48F-1D18A9856A87"},{"full_name":"Ballabio, Andrea","last_name":"Ballabio","first_name":"Andrea"},{"full_name":"Frigerio, Jacopo","last_name":"Frigerio","first_name":"Jacopo"},{"full_name":"Chrastina, Daniel","first_name":"Daniel","last_name":"Chrastina"},{"full_name":"Isella, Giovanni","first_name":"Giovanni","last_name":"Isella"},{"id":"38DB5788-F248-11E8-B48F-1D18A9856A87","full_name":"Katsaros, Georgios","orcid":"0000-0001-8342-202X","last_name":"Katsaros","first_name":"Georgios"}],"ec_funded":1,"arxiv":1,"doi":"10.48550/arXiv.1910.05841","day":"13","abstract":[{"text":"We study double quantum dots in a Ge/SiGe heterostructure and test their maturity towards singlet-triplet ($S-T_0$) qubits. We demonstrate a large range of tunability, from two single quantum dots to a double quantum dot. We measure Pauli spin blockade and study the anisotropy of the $g$-factor. We use an adjacent quantum dot for sensing charge transitions in the double quantum dot at interest. In conclusion, Ge/SiGe possesses all ingredients necessary for building a singlet-triplet qubit.","lang":"eng"}],"date_updated":"2024-03-25T23:30:14Z","year":"2019","citation":{"ista":"Hofmann AC, Jirovec D, Borovkov M, Prieto Gonzalez I, Ballabio A, Frigerio J, Chrastina D, Isella G, Katsaros G. Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits. arXiv, 1910.05841.","short":"A.C. Hofmann, D. Jirovec, M. Borovkov, I. Prieto Gonzalez, A. Ballabio, J. Frigerio, D. Chrastina, G. Isella, G. Katsaros, ArXiv (n.d.).","mla":"Hofmann, Andrea C., et al. “Assessing the Potential of Ge/SiGe Quantum Dots as Hosts for Singlet-Triplet Qubits.” <i>ArXiv</i>, 1910.05841, doi:<a href=\"https://doi.org/10.48550/arXiv.1910.05841\">10.48550/arXiv.1910.05841</a>.","chicago":"Hofmann, Andrea C, Daniel Jirovec, Maxim Borovkov, Ivan Prieto Gonzalez, Andrea Ballabio, Jacopo Frigerio, Daniel Chrastina, Giovanni Isella, and Georgios Katsaros. “Assessing the Potential of Ge/SiGe Quantum Dots as Hosts for Singlet-Triplet Qubits.” <i>ArXiv</i>, n.d. <a href=\"https://doi.org/10.48550/arXiv.1910.05841\">https://doi.org/10.48550/arXiv.1910.05841</a>.","ieee":"A. C. Hofmann <i>et al.</i>, “Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits,” <i>arXiv</i>. .","ama":"Hofmann AC, Jirovec D, Borovkov M, et al. Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits. <i>arXiv</i>. doi:<a href=\"https://doi.org/10.48550/arXiv.1910.05841\">10.48550/arXiv.1910.05841</a>","apa":"Hofmann, A. C., Jirovec, D., Borovkov, M., Prieto Gonzalez, I., Ballabio, A., Frigerio, J., … Katsaros, G. (n.d.). Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits. <i>arXiv</i>. <a href=\"https://doi.org/10.48550/arXiv.1910.05841\">https://doi.org/10.48550/arXiv.1910.05841</a>"},"external_id":{"arxiv":["1910.05841"]},"acknowledgement":"We thank Matthias Brauns for helpful discussions and careful proofreading of the manuscript. This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 844511 and from the FWF project P30207. The research was supported by the Scientific Service Units of IST Austria through resources provided by the MIBA machine shop and the nanofabrication\r\nfacility."}]