[{"oa":1,"abstract":[{"lang":"eng","text":"Gate-tunable transmons (gatemons) employing semiconductor Josephson junctions have recently emerged as building blocks for hybrid quantum circuits. In this study, we present a gatemon fabricated in planar Germanium. We induce superconductivity in a two-dimensional hole gas by evaporating aluminum atop a thin spacer, which separates the superconductor from the Ge quantum well. The Josephson junction is then integrated into an Xmon circuit and capacitively coupled to a transmission line resonator. We showcase the qubit tunability in a broad frequency range with resonator and two-tone spectroscopy. Time-domain characterizations reveal energy relaxation and coherence times up to 75 ns. Our results, combined with the recent advances in the spin qubit field, pave the way towards novel hybrid and protected qubits in a group IV, CMOS-compatible material."}],"month":"07","file":[{"file_name":"2024_NatureComm_Sagi.pdf","file_id":"17388","content_type":"application/pdf","date_updated":"2024-08-05T08:38:01Z","date_created":"2024-08-05T08:38:01Z","creator":"dernst","success":1,"access_level":"open_access","relation":"main_file","file_size":1928001,"checksum":"ddf5361dcb6c543e2cea818501c09910"}],"date_updated":"2026-04-07T13:01:55Z","publication_identifier":{"eissn":["2041-1723"]},"article_type":"original","date_published":"2024-07-30T00:00:00Z","title":"A gate tunable transmon qubit in planar Ge","license":"https://creativecommons.org/licenses/by/4.0/","pmid":1,"type":"journal_article","isi":1,"oa_version":"Published Version","APC_amount":"6828 EUR","arxiv":1,"publication_status":"published","doi":"10.1038/s41467-024-50763-6","file_date_updated":"2024-08-05T08:38:01Z","has_accepted_license":"1","project":[{"name":"Merging spin and superconducting qubits in planar Ge","_id":"bd8bd29e-d553-11ed-ba76-f0070d4b237a","grant_number":"P36507"},{"grant_number":"I05060","_id":"c0977eea-5a5b-11eb-8a69-a862db0cf4d1","name":"High impedance circuit quantum electrodynamics with hole spins"},{"_id":"262116AA-B435-11E9-9278-68D0E5697425","name":"Hybrid Semiconductor - Superconductor Quantum Devices"},{"name":"FWF Open Access Fund","_id":"3AC91DDA-15DF-11EA-824D-93A3E7B544D1","call_identifier":"FWF"}],"ddc":["530"],"external_id":{"isi":["001281271000022"],"pmid":["39080279"],"arxiv":["2403.16774"]},"quality_controlled":"1","citation":{"short":"O. Sagi, A. Crippa, M. Valentini, M. Janik, L. Baghumyan, G. Fabris, L. Kapoor, F. Hassani, J.M. Fink, S. Calcaterra, D. Chrastina, G. Isella, G. Katsaros, Nature Communications 15 (2024).","apa":"Sagi, O., Crippa, A., Valentini, M., Janik, M., Baghumyan, L., Fabris, G., … Katsaros, G. (2024). A gate tunable transmon qubit in planar Ge. <i>Nature Communications</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41467-024-50763-6\">https://doi.org/10.1038/s41467-024-50763-6</a>","chicago":"Sagi, Oliver, Alessandro Crippa, Marco Valentini, Marian Janik, Levon Baghumyan, Giorgio Fabris, Lucky Kapoor, et al. “A Gate Tunable Transmon Qubit in Planar Ge.” <i>Nature Communications</i>. Springer Nature, 2024. <a href=\"https://doi.org/10.1038/s41467-024-50763-6\">https://doi.org/10.1038/s41467-024-50763-6</a>.","ista":"Sagi O, Crippa A, Valentini M, Janik M, Baghumyan L, Fabris G, Kapoor L, Hassani F, Fink JM, Calcaterra S, Chrastina D, Isella G, Katsaros G. 2024. A gate tunable transmon qubit in planar Ge. Nature Communications. 15, 6400.","ama":"Sagi O, Crippa A, Valentini M, et al. A gate tunable transmon qubit in planar Ge. <i>Nature Communications</i>. 2024;15. doi:<a href=\"https://doi.org/10.1038/s41467-024-50763-6\">10.1038/s41467-024-50763-6</a>","ieee":"O. Sagi <i>et al.</i>, “A gate tunable transmon qubit in planar Ge,” <i>Nature Communications</i>, vol. 15. Springer Nature, 2024.","mla":"Sagi, Oliver, et al. “A Gate Tunable Transmon Qubit in Planar Ge.” <i>Nature Communications</i>, vol. 15, 6400, Springer Nature, 2024, doi:<a href=\"https://doi.org/10.1038/s41467-024-50763-6\">10.1038/s41467-024-50763-6</a>."},"publication":"Nature Communications","OA_type":"gold","status":"public","scopus_import":"1","department":[{"_id":"GeKa"},{"_id":"JoFi"},{"_id":"GradSch"}],"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","language":[{"iso":"eng"}],"acknowledgement":"We acknowledge Lucas Casparis, Jeroen Danon, Valla Fatemi, Morten Kjaergard and Javad Shabani for their valuable insights and comments. This research was supported by the Scientific Service Units of ISTA through resources provided by the MIBA Machine Shop\r\nand the Nanofabrication facility. This research and related results were made possible with the support of the NOMIS Foundation and the FWF Projects with DOI:10.55776/I5060 and DOI:10.55776/P36507. We also acknowledge the NextGenerationEU PRIN project\r\n2022A8CJP3 (GAMESQUAD) for partial financial support.","OA_place":"publisher","article_processing_charge":"Yes","intvolume":"        15","article_number":"6400","DOAJ_listed":"1","acknowledged_ssus":[{"_id":"ScienComp"},{"_id":"M-Shop"},{"_id":"NanoFab"}],"publisher":"Springer Nature","year":"2024","tmp":{"image":"/images/cc_by.png","short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"corr_author":"1","day":"30","_id":"17202","author":[{"full_name":"Sagi, Oliver","first_name":"Oliver","last_name":"Sagi","id":"71616374-A8E9-11E9-A7CA-09ECE5697425"},{"first_name":"Alessandro","full_name":"Crippa, Alessandro","orcid":"0000-0002-2968-611X","last_name":"Crippa","id":"1F2B21A2-F6E7-11E9-9B82-F7DBE5697425"},{"first_name":"Marco","full_name":"Valentini, Marco","id":"C0BB2FAC-D767-11E9-B658-BC13E6697425","last_name":"Valentini"},{"last_name":"Janik","id":"396A1950-F248-11E8-B48F-1D18A9856A87","orcid":"0009-0003-9037-8831","first_name":"Marian","full_name":"Janik, Marian"},{"full_name":"Baghumyan, Levon","first_name":"Levon","id":"7aa1f788-b527-11ee-aa9e-e6111a79e0c7","last_name":"Baghumyan"},{"first_name":"Giorgio","full_name":"Fabris, Giorgio","id":"298cf6f3-1ff6-11ee-9fa6-d94cfa0b3352","last_name":"Fabris"},{"last_name":"Kapoor","id":"84b9700b-15b2-11ec-abd3-831089e67615","first_name":"Lucky","full_name":"Kapoor, Lucky","orcid":"0000-0001-8319-2148"},{"orcid":"0000-0001-6937-5773","first_name":"Farid","full_name":"Hassani, Farid","id":"2AED110C-F248-11E8-B48F-1D18A9856A87","last_name":"Hassani"},{"id":"4B591CBA-F248-11E8-B48F-1D18A9856A87","last_name":"Fink","full_name":"Fink, Johannes M","first_name":"Johannes M","orcid":"0000-0001-8112-028X"},{"first_name":"Stefano","full_name":"Calcaterra, Stefano","last_name":"Calcaterra"},{"full_name":"Chrastina, Daniel","first_name":"Daniel","last_name":"Chrastina"},{"last_name":"Isella","full_name":"Isella, Giovanni","first_name":"Giovanni"},{"orcid":"0000-0001-8342-202X","full_name":"Katsaros, Georgios","first_name":"Georgios","last_name":"Katsaros","id":"38DB5788-F248-11E8-B48F-1D18A9856A87"}],"date_created":"2024-07-04T11:40:45Z","related_material":{"record":[{"relation":"research_data","status":"public","id":"17196"},{"id":"18076","relation":"dissertation_contains","status":"public"}],"link":[{"url":"https://doi.org/10.1038/s41467-024-53910-1","relation":"erratum"}]},"volume":15},{"volume":128,"_id":"10920","author":[{"id":"4C473F58-F248-11E8-B48F-1D18A9856A87","last_name":"Jirovec","orcid":"0000-0002-7197-4801","full_name":"Jirovec, Daniel","first_name":"Daniel"},{"first_name":"Philipp M.","full_name":"Mutter, Philipp M.","last_name":"Mutter"},{"last_name":"Hofmann","id":"340F461A-F248-11E8-B48F-1D18A9856A87","full_name":"Hofmann, Andrea C","first_name":"Andrea C"},{"orcid":"0000-0002-2968-611X","full_name":"Crippa, Alessandro","first_name":"Alessandro","last_name":"Crippa","id":"1F2B21A2-F6E7-11E9-9B82-F7DBE5697425"},{"last_name":"Rychetsky","first_name":"Marek","full_name":"Rychetsky, Marek"},{"full_name":"Craig, David L.","first_name":"David L.","last_name":"Craig"},{"id":"3F5D8856-F248-11E8-B48F-1D18A9856A87","last_name":"Kukucka","full_name":"Kukucka, Josip","first_name":"Josip"},{"id":"38F80F9A-1CB8-11EA-BC76-B49B3DDC885E","last_name":"Martins","full_name":"Martins, Frederico","first_name":"Frederico","orcid":"0000-0003-2668-2401"},{"full_name":"Ballabio, Andrea","first_name":"Andrea","last_name":"Ballabio"},{"last_name":"Ares","full_name":"Ares, Natalia","first_name":"Natalia"},{"last_name":"Chrastina","first_name":"Daniel","full_name":"Chrastina, Daniel"},{"last_name":"Isella","first_name":"Giovanni","full_name":"Isella, Giovanni"},{"last_name":"Burkard","full_name":"Burkard, Guido ","first_name":"Guido "},{"orcid":"0000-0001-8342-202X","full_name":"Katsaros, Georgios","first_name":"Georgios","last_name":"Katsaros","id":"38DB5788-F248-11E8-B48F-1D18A9856A87"}],"date_created":"2022-03-24T15:51:11Z","related_material":{"record":[{"id":"18291","status":"public","relation":"popular_science"}]},"corr_author":"1","day":"24","tmp":{"image":"/images/cc_by.png","short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"issue":"12","article_number":"126803","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"publisher":"American Physical Society","year":"2022","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","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.","language":[{"iso":"eng"}],"article_processing_charge":"No","intvolume":"       128","scopus_import":"1","department":[{"_id":"GradSch"},{"_id":"GeKa"}],"ec_funded":1,"external_id":{"isi":["000786542500004"],"pmid":["35394319"],"arxiv":["2111.05130"]},"quality_controlled":"1","citation":{"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>","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>.","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.","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).","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>","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>.","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."},"status":"public","publication":"Physical Review Letters","project":[{"name":"Majorana bound states in Ge/SiGe heterostructures","_id":"26A151DA-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","grant_number":"844511"},{"call_identifier":"H2020","grant_number":"754411","name":"ISTplus - Postdoctoral Fellowships","_id":"260C2330-B435-11E9-9278-68D0E5697425"},{"grant_number":"P30207","call_identifier":"FWF","name":"Hole spin orbit qubits in Ge quantum wells","_id":"2641CE5E-B435-11E9-9278-68D0E5697425"},{"name":"High impedance circuit quantum electrodynamics with hole spins","_id":"c0977eea-5a5b-11eb-8a69-a862db0cf4d1","grant_number":"I05060"},{"grant_number":"M03032","name":"Long-range spin exchange for 2D qubits architectures","_id":"c08c05c4-5a5b-11eb-8a69-dc6ce49d7973"}],"ddc":["530"],"arxiv":1,"has_accepted_license":"1","doi":"10.1103/PhysRevLett.128.126803","file_date_updated":"2022-03-28T06:53:39Z","publication_status":"published","type":"journal_article","isi":1,"oa_version":"Published Version","date_updated":"2025-04-14T07:44:07Z","publication_identifier":{"eissn":["1079-7114"]},"date_published":"2022-03-24T00:00:00Z","article_type":"original","title":"Dynamics of hole singlet-triplet qubits with large g-factor differences","pmid":1,"month":"03","file":[{"creator":"dernst","date_created":"2022-03-28T06:53:39Z","file_name":"2022_PhysRevLetters_Jirovec.pdf","content_type":"application/pdf","file_id":"10928","date_updated":"2022-03-28T06:53:39Z","success":1,"checksum":"6e66ad548d18db9c131f304acbd5a1f4","relation":"main_file","file_size":1266515,"access_level":"open_access"}],"oa":1,"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"}]},{"scopus_import":"1","department":[{"_id":"GeKa"},{"_id":"NanoFab"},{"_id":"GradSch"}],"ec_funded":1,"external_id":{"arxiv":["2011.13755"],"pmid":["34083775"],"isi":["000657596400001"]},"citation":{"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>","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.","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>.","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>","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.","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>.","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."},"quality_controlled":"1","publication":"Nature Materials","status":"public","issue":"8","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"publisher":"Springer Nature","year":"2021","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","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.","language":[{"iso":"eng"}],"intvolume":"        20","article_processing_charge":"No","corr_author":"1","day":"01","volume":20,"_id":"8909","page":"1106–1112","author":[{"first_name":"Daniel","full_name":"Jirovec, Daniel","orcid":"0000-0002-7197-4801","id":"4C473F58-F248-11E8-B48F-1D18A9856A87","last_name":"Jirovec"},{"last_name":"Hofmann","id":"340F461A-F248-11E8-B48F-1D18A9856A87","full_name":"Hofmann, Andrea C","first_name":"Andrea C"},{"last_name":"Ballabio","full_name":"Ballabio, Andrea","first_name":"Andrea"},{"last_name":"Mutter","first_name":"Philipp M.","full_name":"Mutter, Philipp M."},{"last_name":"Tavani","full_name":"Tavani, Giulio","first_name":"Giulio"},{"last_name":"Botifoll","first_name":"Marc","full_name":"Botifoll, Marc"},{"full_name":"Crippa, Alessandro","first_name":"Alessandro","orcid":"0000-0002-2968-611X","id":"1F2B21A2-F6E7-11E9-9B82-F7DBE5697425","last_name":"Crippa"},{"last_name":"Kukucka","id":"3F5D8856-F248-11E8-B48F-1D18A9856A87","first_name":"Josip","full_name":"Kukucka, Josip"},{"full_name":"Sagi, Oliver","first_name":"Oliver","last_name":"Sagi","id":"71616374-A8E9-11E9-A7CA-09ECE5697425"},{"id":"38F80F9A-1CB8-11EA-BC76-B49B3DDC885E","last_name":"Martins","first_name":"Frederico","full_name":"Martins, Frederico","orcid":"0000-0003-2668-2401"},{"full_name":"Saez Mollejo, Jaime","first_name":"Jaime","last_name":"Saez Mollejo","id":"e0390f72-f6e0-11ea-865d-862393336714"},{"orcid":"0000-0002-7370-5357","first_name":"Ivan","full_name":"Prieto Gonzalez, Ivan","id":"2A307FE2-F248-11E8-B48F-1D18A9856A87","last_name":"Prieto Gonzalez"},{"full_name":"Borovkov, Maksim","first_name":"Maksim","id":"2ac7a0a2-3562-11eb-9256-fbd18ea55087","last_name":"Borovkov"},{"last_name":"Arbiol","first_name":"Jordi","full_name":"Arbiol, Jordi"},{"first_name":"Daniel","full_name":"Chrastina, Daniel","last_name":"Chrastina"},{"full_name":"Isella, Giovanni","first_name":"Giovanni","last_name":"Isella"},{"orcid":"0000-0001-8342-202X","first_name":"Georgios","full_name":"Katsaros, Georgios","id":"38DB5788-F248-11E8-B48F-1D18A9856A87","last_name":"Katsaros"}],"date_created":"2020-12-02T10:50:47Z","related_material":{"record":[{"id":"9323","status":"public","relation":"research_data"},{"relation":"dissertation_contains","status":"public","id":"10058"}],"link":[{"description":"News on IST Homepage","relation":"press_release","url":"https://ist.ac.at/en/news/quantum-computing-with-holes/"}]},"oa":1,"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"}],"publication_identifier":{"eissn":["1476-4660"],"issn":["1476-1122"]},"date_updated":"2026-07-05T22:30:43Z","article_type":"original","date_published":"2021-08-01T00:00:00Z","title":"A singlet triplet hole spin qubit in planar Ge","pmid":1,"month":"08","arxiv":1,"doi":"10.1038/s41563-021-01022-2","publication_status":"published","isi":1,"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/2011.13755"}],"type":"journal_article","oa_version":"Preprint","project":[{"_id":"26A151DA-B435-11E9-9278-68D0E5697425","name":"Majorana bound states in Ge/SiGe heterostructures","grant_number":"844511","call_identifier":"H2020"},{"call_identifier":"H2020","grant_number":"754411","name":"ISTplus - Postdoctoral Fellowships","_id":"260C2330-B435-11E9-9278-68D0E5697425"},{"call_identifier":"FWF","grant_number":"P30207","_id":"2641CE5E-B435-11E9-9278-68D0E5697425","name":"Hole spin orbit qubits in Ge quantum wells"},{"_id":"262116AA-B435-11E9-9278-68D0E5697425","name":"Hybrid Semiconductor - Superconductor Quantum Devices"}]}]