[{"issue":"3","das_tickbox":"1","corr_author":"1","month":"07","status":"public","publication":"Applied Physics Letters","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"abstract":[{"lang":"eng","text":"Planar germanium is currently the only semiconducting platform where high-coherence spin qubits and proximity-induced superconductivity have each been demonstrated. Recent research into spin qubits in Ge/SiGe heterostructures has focused on increasing the thickness of the SiGe capping layer, reporting improvements in the electrostatic noise levels. Meanwhile, heterostructures with thinner capping layers remain rather unexplored, despite the potential advantages for proximity-induced superconductivity. Here, we study a Ge/SiGe heterostructure with a thin SiGe cap d - 4nm and investigate its viability to host low-noise quantum dots. To keep the thermal budget compatible with superconducting layers, low-temperature oxide deposition processes were developed and implemented for the gate dielectrics. The charge noise level of the fabricated devices is estimated to be 1.8  +- 1.0 μeV/ square HZ⁠, comparable to devices fabricated on shallow heterostructures (⁠ d - 20nm⁠) with high-temperature deposited oxides. Low charge noise levels, together with the straightforward integration of superconductors, make this heterostructure an attractive platform for prototyping hybrid semiconducting–superconducting devices."}],"date_created":"2026-08-02T22:01:53Z","publisher":"AIP Publishing","supplementarymaterial":"yes","language":[{"iso":"eng"}],"OA_type":"green","intvolume":"       129","publication_status":"published","article_processing_charge":"No","year":"2026","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_published":"2026-07-20T00:00:00Z","article_number":"033505","type":"journal_article","oa":1,"_id":"22619","quality_controlled":"1","oa_version":"Preprint","main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.2602.21363"}],"scopus_import":"1","department":[{"_id":"GeKa"},{"_id":"GradSch"},{"_id":"NanoFab"}],"volume":129,"project":[{"name":"Quantum bits with Kitaev Transmons","grant_number":"101115315","_id":"bdc2ca30-d553-11ed-ba76-cf164a5bb811"},{"_id":"34a66131-11ca-11ed-8bc3-a31681c6b03e","grant_number":"F8606","name":"Center for Correlated Quantum Materials and Solid State Quantum Systems: Conventional  and unconventional topological superconductors"},{"_id":"5b9e579c-ab3d-11f0-914f-88754c5b5a3f","grant_number":"PAT 7682124","name":"Superconducting spin qubits in planar Ge"},{"_id":"bd8bd29e-d553-11ed-ba76-f0070d4b237a","grant_number":"P36507","name":"Merging spin and superconducting qubits in planar Ge"},{"_id":"8ea8abf7-16d5-11f0-9cad-c41e56ec8bb3","grant_number":"101150858","name":"Realization and Manipulation of a Planar hybrid superconducting Andreev spin qubit in Germanium"}],"doi":"10.1063/5.0333142","citation":{"chicago":"Borovkov, Maksim, Yona A Schell, Dina Sokolova, Kevin Etienne Robert Roux, Paul Falthansl-Scheinecker, Giorgio Fabris, Devashish C Shah, et al. “Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping Hybrid Semiconducting–Superconducting Devices.” <i>Applied Physics Letters</i>. AIP Publishing, 2026. <a href=\"https://doi.org/10.1063/5.0333142\">https://doi.org/10.1063/5.0333142</a>.","short":"M. Borovkov, Y.A. Schell, D. Sokolova, K.E.R. Roux, P. Falthansl-Scheinecker, G. Fabris, D.C. Shah, J. Saez Mollejo, R. Previdi, I. Taha, A. Genç, J. Arbiol, S. Calcaterra, A.D.C. Oliveira, D. Chrastina, G. Isella, A. Bubis, G. Katsaros, Applied Physics Letters 129 (2026).","ieee":"M. Borovkov <i>et al.</i>, “Low-noise quantum dots in ultra-shallow Ge/SiGe heterostructures for prototyping hybrid semiconducting–superconducting devices,” <i>Applied Physics Letters</i>, vol. 129, no. 3. AIP Publishing, 2026.","mla":"Borovkov, Maksim, et al. “Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping Hybrid Semiconducting–Superconducting Devices.” <i>Applied Physics Letters</i>, vol. 129, no. 3, 033505, AIP Publishing, 2026, doi:<a href=\"https://doi.org/10.1063/5.0333142\">10.1063/5.0333142</a>.","ista":"Borovkov M, Schell YA, Sokolova D, Roux KER, Falthansl-Scheinecker P, Fabris G, Shah DC, Saez Mollejo J, Previdi R, Taha I, Genç A, Arbiol J, Calcaterra S, Oliveira ADC, Chrastina D, Isella G, Bubis A, Katsaros G. 2026. Low-noise quantum dots in ultra-shallow Ge/SiGe heterostructures for prototyping hybrid semiconducting–superconducting devices. Applied Physics Letters. 129(3), 033505.","ama":"Borovkov M, Schell YA, Sokolova D, et al. Low-noise quantum dots in ultra-shallow Ge/SiGe heterostructures for prototyping hybrid semiconducting–superconducting devices. <i>Applied Physics Letters</i>. 2026;129(3). doi:<a href=\"https://doi.org/10.1063/5.0333142\">10.1063/5.0333142</a>","apa":"Borovkov, M., Schell, Y. A., Sokolova, D., Roux, K. E. R., Falthansl-Scheinecker, P., Fabris, G., … Katsaros, G. (2026). Low-noise quantum dots in ultra-shallow Ge/SiGe heterostructures for prototyping hybrid semiconducting–superconducting devices. <i>Applied Physics Letters</i>. AIP Publishing. <a href=\"https://doi.org/10.1063/5.0333142\">https://doi.org/10.1063/5.0333142</a>"},"author":[{"full_name":"Borovkov, Maksim","id":"1fd0975f-8b61-11ed-b69e-d149334f28c5","first_name":"Maksim","last_name":"Borovkov"},{"last_name":"Schell","first_name":"Yona A","full_name":"Schell, Yona A","id":"fe39122d-06bb-11ec-a33b-9e22b40e40a5"},{"last_name":"Sokolova","first_name":"Dina","id":"2d2d62f8-72f0-11ef-b75a-8ec3e8a60032","full_name":"Sokolova, Dina"},{"first_name":"Kevin Etienne Robert","last_name":"Roux","full_name":"Roux, Kevin Etienne Robert","id":"53f93ea2-803f-11ed-ab7e-b283135794ef"},{"first_name":"Paul","last_name":"Falthansl-Scheinecker","id":"85b43b21-15b2-11ec-abd3-e2c252cc2285","full_name":"Falthansl-Scheinecker, Paul"},{"full_name":"Fabris, Giorgio","id":"298cf6f3-1ff6-11ee-9fa6-d94cfa0b3352","first_name":"Giorgio","last_name":"Fabris"},{"full_name":"Shah, Devashish C","id":"de191434-4e7e-11ef-bf4b-9a056fc19fc3","last_name":"Shah","orcid":"0009-0007-5829-7707","first_name":"Devashish C"},{"id":"e0390f72-f6e0-11ea-865d-862393336714","full_name":"Saez Mollejo, Jaime","last_name":"Saez Mollejo","first_name":"Jaime"},{"id":"bc4ea1dc-00ce-11ec-8a4e-b325ca8b9876","full_name":"Previdi, Rodolfo","last_name":"Previdi","first_name":"Rodolfo"},{"full_name":"Taha, Inas","first_name":"Inas","last_name":"Taha"},{"full_name":"Genç, Aziz","last_name":"Genç","first_name":"Aziz"},{"first_name":"Jordi","last_name":"Arbiol","full_name":"Arbiol, Jordi"},{"full_name":"Calcaterra, Stefano","last_name":"Calcaterra","first_name":"Stefano"},{"first_name":"Afonso De Cerdeira","last_name":"Oliveira","full_name":"Oliveira, Afonso De Cerdeira"},{"first_name":"Daniel","last_name":"Chrastina","full_name":"Chrastina, Daniel"},{"full_name":"Isella, Giovanni","first_name":"Giovanni","last_name":"Isella"},{"first_name":"Anton","last_name":"Bubis","id":"1f6212b5-f795-11ec-9c0c-de4780302890","full_name":"Bubis, Anton"},{"id":"38DB5788-F248-11E8-B48F-1D18A9856A87","full_name":"Katsaros, Georgios","orcid":"0000-0001-8342-202X","last_name":"Katsaros","first_name":"Georgios"}],"dataavailabilitystatement":"The data that support the findings of this study are openly available in Institute of Science and Technology repository at http://doi.org/10.15479/AT-ISTA-22242, Ref. 50.","title":"Low-noise quantum dots in ultra-shallow Ge/SiGe heterostructures for prototyping hybrid semiconducting–superconducting devices","researchdata_availability":"yes","date_updated":"2026-08-03T11:08:39Z","day":"20","related_material":{"record":[{"relation":"research_data","id":"22242","status":"public"}]},"acknowledgement":"We sincerely thank Nick van Loo, Greg Mazur, Dhananjay Joshi, and Srijit Goswami for their inputs on low-temperature HfOx deposition; Matias Urdampilleta and Daniel Jirovec for discussions; and Kristen Léonard for the careful reading of the manuscript. This research was supported by the Scientific Service Units of ISTA through resources provided by the Miba Machine Shop and the Nanofabrication facility. The authors acknowledge support from the NOMIS Foundation; the European Innovation Council Pathfinder Grant No. 101115315 (QuKiT); the FWF Projects with DOI:10.55776/F86, DOI:10.55776/PAT7682124, and DOI:10.55776/P36507; and the HE-MSCA-PF project with DOI:10.3030/101150858. ICN2 is supported by the Severo Ochoa Program from Spanish MCIN/AEI (Grant No.: CEX2021-001214-S) and is funded by the CERCA Program/Generalitat de Catalunya. ICN2 acknowledges funding from Generalitat de Catalunya (No. 2021SGR00457). We acknowledge support from the CSIC Interdisciplinary Thematic Platform (PTI+) on Quantum Technologies (PTI-QTEP+).","article_type":"original","publication_identifier":{"issn":["0003-6951"],"eissn":["1077-3118"]},"arxiv":1,"OA_place":"repository","external_id":{"arxiv":["2602.21363"]}},{"file":[{"relation":"main_file","date_created":"2025-03-17T08:48:09Z","file_name":"AllDataPublished.zip","checksum":"1f21c8ea2196776aae51cc3a5d00e00b","creator":"jsaezmol","file_size":21971911,"content_type":"application/x-zip-compressed","access_level":"open_access","success":1,"file_id":"19410","date_updated":"2025-03-17T08:48:09Z"}],"year":"2025","article_processing_charge":"No","date_published":"2025-03-17T00:00:00Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa":1,"type":"research_data","corr_author":"1","ddc":["530"],"month":"03","status":"public","acknowledged_ssus":[{"_id":"NanoFab"},{"_id":"M-Shop"}],"publisher":"Institute of Science and Technology Austria","abstract":[{"lang":"eng","text":"This .zip file contains the data to reproduce the figures and supplementary figures of \"Exchange anisotropies in microwave-driven singlet-triplet qubits\" by Jaime Saez-Mollejo et al.\r\n"}],"date_created":"2025-03-17T08:57:09Z","has_accepted_license":"1","OA_type":"gold","author":[{"full_name":"Saez Mollejo, Jaime","id":"e0390f72-f6e0-11ea-865d-862393336714","last_name":"Saez Mollejo","first_name":"Jaime"}],"title":"Exchange anisotropies in microwave-driven singlet-triplet qubits","date_updated":"2026-05-20T06:42:16Z","day":"17","related_material":{"record":[{"id":"19424","relation":"used_in_publication","status":"public"}]},"file_date_updated":"2025-03-17T08:48:09Z","acknowledgement":"We thank A. Crippa for helpful discussions. This research was supported by the Scientific Service Units of ISTA through resources provided by the MIBA Machine Shop and the Nanofabrication facility. This research and related results were made possible with the support of the NOMIS Foundation, the HORIZON-RIA 101069515 project and the FWF Projects \r\nwith DOI:10.55776/F86 and DOI:10.55776/I5060. M.R.-R. acknowledges support from the Netherlands Organization of\r\n scientific Research (NWO) under Veni grant VI.Veni.212.223. The Research of S.B. and M.R.-R. was sponsored in part by the Army Research Office and was accomplished under Award Number: W911NF-23-1-0110.","OA_place":"publisher","license":"https://creativecommons.org/licenses/by/4.0/","contributor":[{"last_name":"Jirovec","orcid":"0000-0002-7197-4801","first_name":"Daniel","id":"4C473F58-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Schell","first_name":"Yona A","id":"fe39122d-06bb-11ec-a33b-9e22b40e40a5"},{"first_name":"Josip","last_name":"Kukucka","id":"3F5D8856-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Calcaterra","first_name":"Stefano"},{"first_name":"Daniel ","last_name":"Chrastina"},{"first_name":"Giovanni ","last_name":"Isella"},{"first_name":"Maximilian","last_name":"Rimbach-Russ"},{"first_name":"Stefano","last_name":"Bosco"},{"last_name":"Katsaros","orcid":"0000-0001-8342-202X","first_name":"Georgios","id":"38DB5788-F248-11E8-B48F-1D18A9856A87"}],"oa_version":"Published Version","_id":"19409","department":[{"_id":"GradSch"},{"_id":"GeKa"}],"tmp":{"image":"/images/cc_by.png","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"citation":{"ama":"Saez Mollejo J. Exchange anisotropies in microwave-driven singlet-triplet qubits. 2025. doi:<a href=\"https://doi.org/10.15479/AT:ISTA:19409\">10.15479/AT:ISTA:19409</a>","ista":"Saez Mollejo J. 2025. Exchange anisotropies in microwave-driven singlet-triplet qubits, Institute of Science and Technology Austria, <a href=\"https://doi.org/10.15479/AT:ISTA:19409\">10.15479/AT:ISTA:19409</a>.","apa":"Saez Mollejo, J. (2025). Exchange anisotropies in microwave-driven singlet-triplet qubits. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT:ISTA:19409\">https://doi.org/10.15479/AT:ISTA:19409</a>","mla":"Saez Mollejo, Jaime. <i>Exchange Anisotropies in Microwave-Driven Singlet-Triplet Qubits</i>. Institute of Science and Technology Austria, 2025, doi:<a href=\"https://doi.org/10.15479/AT:ISTA:19409\">10.15479/AT:ISTA:19409</a>.","ieee":"J. Saez Mollejo, “Exchange anisotropies in microwave-driven singlet-triplet qubits.” Institute of Science and Technology Austria, 2025.","short":"J. Saez Mollejo, (2025).","chicago":"Saez Mollejo, Jaime. “Exchange Anisotropies in Microwave-Driven Singlet-Triplet Qubits.” Institute of Science and Technology Austria, 2025. <a href=\"https://doi.org/10.15479/AT:ISTA:19409\">https://doi.org/10.15479/AT:ISTA:19409</a>."},"doi":"10.15479/AT:ISTA:19409","project":[{"name":"Integrated Germanium Quantum Technology","grant_number":"101069515","_id":"34c0acea-11ca-11ed-8bc3-8775e10fd452"},{"name":"High impedance circuit quantum electrodynamics with hole spins","grant_number":"I05060","_id":"c0977eea-5a5b-11eb-8a69-a862db0cf4d1"},{"name":"Center for Correlated Quantum Materials and Solid State Quantum Systems: Conventional  and unconventional topological superconductors","grant_number":"F8606","_id":"34a66131-11ca-11ed-8bc3-a31681c6b03e"}]},{"author":[{"id":"e0390f72-f6e0-11ea-865d-862393336714","full_name":"Saez Mollejo, Jaime","last_name":"Saez Mollejo","first_name":"Jaime"}],"file":[{"date_updated":"2025-06-24T15:14:13Z","file_id":"19893","success":1,"file_size":3404814792,"content_type":"application/x-zip-compressed","access_level":"open_access","relation":"main_file","date_created":"2025-06-24T15:14:13Z","creator":"jsaezmol","file_name":"DatasetsPaper.zip","checksum":"eff1ae9e46599fdfab8da00a2ca3c289"},{"relation":"main_file","date_created":"2025-06-25T07:11:52Z","checksum":"21840ceac04d677a799b8e5bd919804f","file_name":"README.txt","creator":"jsaezmol","file_size":622,"content_type":"text/plain","access_level":"open_access","success":1,"file_id":"19899","date_updated":"2025-06-25T07:11:52Z"}],"year":"2025","article_processing_charge":"No","title":"Automated All-RF Tuning for Spin Qubit Readout and Control","date_updated":"2025-07-01T07:19:26Z","date_published":"2025-06-01T00:00:00Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","day":"01","file_date_updated":"2025-06-25T07:11:52Z","acknowledgement":"The authors would like to thank Barnaby van Straaten, Jonas Schuff, Daniel Jirovec and Hanifa Tidjani for fruitful discussions. This research was supported by the Scientific Service Units of ISTA through resources provided by the MIBA Machine Shop and the Nanofabrication Facility. G.K. acknowledges support from the NOMIS Foundation, the HORIZON-RIA (project no. 101069515) and the FWF Projects (DOIs: 10.55776/F86 and 10.55776/I5060). N.A. acknowledges support from the European Research Council (grant agreement 948932), and the Royal Society (grant no. URF/R1/191150). This project received support from the US Army Research Office (ARO) under Award No. W911NF-24-2-0043. C.C. acknowledges support from the UKRI Doctoral Training Partnership related to EP/W524311/1 (project ref. 2887634).","oa":1,"contributor":[{"first_name":"Cornelius","last_name":"Carlsson","contributor_type":"researcher"},{"first_name":"Federico ","last_name":"Fedele","contributor_type":"researcher"},{"contributor_type":"researcher","first_name":"Stefano","last_name":"Calcaterra"},{"first_name":" Daniel ","last_name":"Chrastina","contributor_type":"researcher"},{"contributor_type":"researcher","first_name":"Giovanni ","last_name":"Isella"},{"first_name":"Georgios","last_name":"Katsaros","orcid":"0000-0001-8342-202X","id":"38DB5788-F248-11E8-B48F-1D18A9856A87","contributor_type":"researcher"},{"first_name":"Natalia","last_name":"Ares","contributor_type":"researcher"}],"type":"research_data","month":"06","corr_author":"1","oa_version":"Published Version","ddc":["530"],"status":"public","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"_id":"19885","publisher":"Institute of Science and Technology Austria","has_accepted_license":"1","department":[{"_id":"GradSch"},{"_id":"GeKa"}],"date_created":"2025-06-24T06:56:03Z","abstract":[{"lang":"eng","text":"This .zip file contains the data to reproduce the figures and supplementary figures of \"Automated All-RF Tuning for Spin Qubit Readout and Control\" by Cornelius Carlsson and Jaime Saez-Mollejo et al."}],"tmp":{"image":"/images/cc_by.png","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"doi":"10.15479/AT:ISTA:19885","citation":{"mla":"Saez Mollejo, Jaime. <i>Automated All-RF Tuning for Spin Qubit Readout and Control</i>. Institute of Science and Technology Austria, 2025, doi:<a href=\"https://doi.org/10.15479/AT:ISTA:19885\">10.15479/AT:ISTA:19885</a>.","ieee":"J. Saez Mollejo, “Automated All-RF Tuning for Spin Qubit Readout and Control.” Institute of Science and Technology Austria, 2025.","apa":"Saez Mollejo, J. (2025). Automated All-RF Tuning for Spin Qubit Readout and Control. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT:ISTA:19885\">https://doi.org/10.15479/AT:ISTA:19885</a>","ama":"Saez Mollejo J. Automated All-RF Tuning for Spin Qubit Readout and Control. 2025. doi:<a href=\"https://doi.org/10.15479/AT:ISTA:19885\">10.15479/AT:ISTA:19885</a>","ista":"Saez Mollejo J. 2025. Automated All-RF Tuning for Spin Qubit Readout and Control, Institute of Science and Technology Austria, <a href=\"https://doi.org/10.15479/AT:ISTA:19885\">10.15479/AT:ISTA:19885</a>.","chicago":"Saez Mollejo, Jaime. “Automated All-RF Tuning for Spin Qubit Readout and Control.” Institute of Science and Technology Austria, 2025. <a href=\"https://doi.org/10.15479/AT:ISTA:19885\">https://doi.org/10.15479/AT:ISTA:19885</a>.","short":"J. Saez Mollejo, (2025)."},"project":[{"_id":"34c0acea-11ca-11ed-8bc3-8775e10fd452","name":"Integrated Germanium Quantum Technology","grant_number":"101069515"},{"_id":"c0977eea-5a5b-11eb-8a69-a862db0cf4d1","grant_number":"I05060","name":"High impedance circuit quantum electrodynamics with hole spins"},{"_id":"34a66131-11ca-11ed-8bc3-a31681c6b03e","grant_number":"F8606","name":"Center for Correlated Quantum Materials and Solid State Quantum Systems: Conventional  and unconventional topological superconductors"}]},{"issue":"20","status":"public","publication":"Physical Review Letters","month":"11","ddc":["530"],"publisher":"American Physical Society","has_accepted_license":"1","abstract":[{"lang":"eng","text":"We experimentally realize a quantum clock by using a charge sensor to count charges tunneling through a double quantum dot (DQD). Individual tunneling events are used as the clock’s ticks. We quantify the clock’s precision while measuring the power dissipated by the DQD and, separately, the charge sensor in both direct-current and radio-frequency readout modes. This allows us to probe the thermodynamic cost of creating ticks microscopically and recording them macroscopically. Our experiment is the first to explore the interplay between the entropy produced by a microscopic clockwork and its macroscopic measurement apparatus. We show that the latter contribution not only dwarfs the former but also unlocks greatly increased precision, because the measurement record can be exploited to optimally estimate time even when the DQD is at equilibrium. Our results suggest that the entropy produced by the amplification and measurement of a clock’s ticks, which has often been ignored in the literature, is the most important and fundamental thermodynamic cost of timekeeping at the quantum scale."}],"date_created":"2025-11-30T23:02:07Z","intvolume":"       135","PlanS_conform":"1","OA_type":"hybrid","language":[{"iso":"eng"}],"file":[{"file_size":444198,"content_type":"application/pdf","access_level":"open_access","relation":"main_file","date_created":"2025-12-01T08:28:00Z","creator":"dernst","file_name":"2025_PhysReviewLetters_Wadhia.pdf","checksum":"e5c89b95d0f52a38f2d2ada3483f3576","date_updated":"2025-12-01T08:28:00Z","success":1,"file_id":"20718"}],"publication_status":"published","article_processing_charge":"Yes (in subscription journal)","year":"2025","article_number":"200407","date_published":"2025-11-14T00:00:00Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","oa":1,"isi":1,"type":"journal_article","quality_controlled":"1","oa_version":"Published Version","_id":"20706","volume":135,"scopus_import":"1","department":[{"_id":"GeKa"}],"tmp":{"image":"/images/cc_by.png","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"doi":"10.1103/5rtj-djfk","citation":{"short":"V. Wadhia, F. Meier, F. Fedele, R. Silva, N. Nurgalieva, D.L. Craig, D. Jirovec, J. Saez Mollejo, A. Ballabio, D. Chrastina, G. Isella, M. Huber, M.T. Mitchison, P. Erker, N. Ares, Physical Review Letters 135 (2025).","chicago":"Wadhia, Vivek, Florian Meier, Federico Fedele, Ralph Silva, Nuriya Nurgalieva, David L. Craig, Daniel Jirovec, et al. “Entropic Costs of Extracting Classical Ticks from a Quantum Clock.” <i>Physical Review Letters</i>. American Physical Society, 2025. <a href=\"https://doi.org/10.1103/5rtj-djfk\">https://doi.org/10.1103/5rtj-djfk</a>.","ama":"Wadhia V, Meier F, Fedele F, et al. Entropic costs of extracting classical ticks from a quantum clock. <i>Physical Review Letters</i>. 2025;135(20). doi:<a href=\"https://doi.org/10.1103/5rtj-djfk\">10.1103/5rtj-djfk</a>","ista":"Wadhia V, Meier F, Fedele F, Silva R, Nurgalieva N, Craig DL, Jirovec D, Saez Mollejo J, Ballabio A, Chrastina D, Isella G, Huber M, Mitchison MT, Erker P, Ares N. 2025. Entropic costs of extracting classical ticks from a quantum clock. Physical Review Letters. 135(20), 200407.","apa":"Wadhia, V., Meier, F., Fedele, F., Silva, R., Nurgalieva, N., Craig, D. L., … Ares, N. (2025). Entropic costs of extracting classical ticks from a quantum clock. <i>Physical Review Letters</i>. American Physical Society. <a href=\"https://doi.org/10.1103/5rtj-djfk\">https://doi.org/10.1103/5rtj-djfk</a>","ieee":"V. Wadhia <i>et al.</i>, “Entropic costs of extracting classical ticks from a quantum clock,” <i>Physical Review Letters</i>, vol. 135, no. 20. American Physical Society, 2025.","mla":"Wadhia, Vivek, et al. “Entropic Costs of Extracting Classical Ticks from a Quantum Clock.” <i>Physical Review Letters</i>, vol. 135, no. 20, 200407, American Physical Society, 2025, doi:<a href=\"https://doi.org/10.1103/5rtj-djfk\">10.1103/5rtj-djfk</a>."},"author":[{"first_name":"Vivek","last_name":"Wadhia","full_name":"Wadhia, Vivek"},{"full_name":"Meier, Florian","first_name":"Florian","last_name":"Meier"},{"last_name":"Fedele","first_name":"Federico","full_name":"Fedele, Federico"},{"full_name":"Silva, Ralph","first_name":"Ralph","last_name":"Silva"},{"last_name":"Nurgalieva","first_name":"Nuriya","full_name":"Nurgalieva, Nuriya"},{"full_name":"Craig, David L.","first_name":"David L.","last_name":"Craig"},{"first_name":"Daniel","last_name":"Jirovec","orcid":"0000-0002-7197-4801","full_name":"Jirovec, Daniel","id":"4C473F58-F248-11E8-B48F-1D18A9856A87"},{"full_name":"Saez Mollejo, Jaime","id":"e0390f72-f6e0-11ea-865d-862393336714","last_name":"Saez Mollejo","first_name":"Jaime"},{"first_name":"Andrea","last_name":"Ballabio","full_name":"Ballabio, Andrea"},{"last_name":"Chrastina","first_name":"Daniel","full_name":"Chrastina, Daniel"},{"full_name":"Isella, Giovanni","last_name":"Isella","first_name":"Giovanni"},{"full_name":"Huber, Marcus","first_name":"Marcus","last_name":"Huber"},{"full_name":"Mitchison, Mark T.","last_name":"Mitchison","first_name":"Mark T."},{"full_name":"Erker, Paul","last_name":"Erker","first_name":"Paul"},{"full_name":"Ares, Natalia","first_name":"Natalia","last_name":"Ares"}],"title":"Entropic costs of extracting classical ticks from a quantum clock","date_updated":"2025-12-01T15:39:14Z","arxiv":1,"day":"14","acknowledgement":"The authors thank Georgios Katsaros for providing the device for this experiment, and Tony Apollaro, Ilia Khomchenko, and Gerard Milburn for discussions. V. W. acknowledges funding from UK Research and Innovation Grant No. EP/T517811/1. F. M., M. H., and P. E. acknowledge funding from the European Research Council (Consolidator Grant “Cocoquest” No. 101043705). M. H. and P. E. acknowledge funding from the Austrian Federal Ministry of Education, Science, and Research via the Austrian Research Promotion Agency (FFG) through Quantum Austria. R. S. acknowledges funding from the Swiss National Science Foundation via an Ambizione Grant No. PZ00P2_185986. M. T. M. is supported by a Royal Society University Research Fellowship. N. A. acknowledges support from the European Research Council (Grant Agreement No, 948932) and the Royal Society (No. URF-R1-191150). This project is cofunded by the European Union (Quantum Flagship project ASPECTS, Grant Agreement No. 101080167) and UK Research and Innovation (UKRI). Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union, Research Executive Agency, or UKRI. Neither the European Union nor UKRI can be held responsible for them.","publication_identifier":{"issn":["0031-9007"],"eissn":["1079-7114"]},"article_type":"original","file_date_updated":"2025-12-01T08:28:00Z","external_id":{"isi":["001619305100001"],"arxiv":["2502.00096"]},"OA_place":"publisher"},{"isi":1,"type":"journal_article","oa":1,"publication_status":"published","article_processing_charge":"Yes","year":"2025","file":[{"relation":"main_file","date_created":"2025-05-05T07:08:23Z","checksum":"13fe84cddc9d4e47213bf17acdac70d7","creator":"dernst","file_name":"2025_NatureComm_SaezMollejo.pdf","file_size":1548756,"content_type":"application/pdf","access_level":"open_access","success":1,"file_id":"19645","date_updated":"2025-05-05T07:08:23Z"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_published":"2025-04-24T00:00:00Z","article_number":"3862","date_created":"2025-03-19T13:28:12Z","pmid":1,"has_accepted_license":"1","abstract":[{"lang":"eng","text":"Hole spin qubits are rapidly emerging as the workhorse of semiconducting quantum processors because of their large spin-orbit interaction, enabling fast all-electric operations at low power. However, spin-orbit interaction also causes non-uniformities in devices, resulting in locally varying qubit energies and site-dependent anisotropies. While these anisotropies can be used to drive single-spins, if not properly harnessed, they can hinder the path toward large-scale quantum processors. Here, we report on microwave-driven singlet-triplet qubits in planar germanium and use them to investigate the anisotropy of two spins in a double quantum dot. We show two distinct operating regimes depending on the magnetic field direction. For in-plane fields, the two spins are largely anisotropic, and electrically tunable, which enables to measure all the available transitions; coherence times exceeding 3 $\\mu$s are extracted. For out-of-plane fields, they have an isotropic response but preserve the substantial energy difference required to address the singlet-triplet qubit. Even in this field direction, where the qubit lifetime\r\nis strongly affected by nuclear spins, we find 400 ns coherence times. Our work adds a valuable tool to investigate and harness the anisotropy of spin qubits and can be implemented in any large-scale NxN device, facilitating the path towards scalable quantum processors."}],"publisher":"Springer Nature","language":[{"iso":"eng"}],"OA_type":"gold","intvolume":"        16","publication":"Nature Communications","month":"04","corr_author":"1","status":"public","ddc":["530"],"acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"day":"24","publication_identifier":{"eissn":["2041-1723"]},"article_type":"original","related_material":{"link":[{"description":"News on ISTA website","relation":"research_data","url":"https://ista.ac.at/en/news/the-shadow-of-an-electron/"}],"record":[{"id":"19409","relation":"research_data","status":"public"},{"id":"19836","relation":"dissertation_contains","status":"public"}]},"file_date_updated":"2025-05-05T07:08:23Z","acknowledgement":"We thank A. Crippa for helpful discussions. This research was supported by the Scientific Service Units of ISTA through resources provided by the MIBA Machine Shop and the Nanofabrication facility. This research and related results were made possible with the support of the NOMIS Foundation, the HORIZON-RIA 101069515 project and the FWF Projects with DOI:10.55776/F86 and DOI:10.55776/I5060. M.R.-R. acknowledges support from the Netherlands Organization of Scientific Research (NWO) under Veni grant VI.Veni.212.223. The\r\nResearch of S.B. and M.R.-R. was sponsored in part by the Army Research Office and was accomplished under Award Number: W911NF-23-1-0110. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Army Research Office or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein.","arxiv":1,"DOAJ_listed":"1","OA_place":"publisher","external_id":{"isi":["001475587400022"],"pmid":["40274808"],"arxiv":["2408.03224"]},"author":[{"last_name":"Saez Mollejo","first_name":"Jaime","id":"e0390f72-f6e0-11ea-865d-862393336714","full_name":"Saez Mollejo, Jaime"},{"last_name":"Jirovec","orcid":"0000-0002-7197-4801","first_name":"Daniel","full_name":"Jirovec, Daniel","id":"4C473F58-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Yona A","last_name":"Schell","id":"fe39122d-06bb-11ec-a33b-9e22b40e40a5","full_name":"Schell, Yona A"},{"full_name":"Kukucka, Josip","id":"3F5D8856-F248-11E8-B48F-1D18A9856A87","first_name":"Josip","last_name":"Kukucka"},{"full_name":"Calcaterra, Stefano","first_name":"Stefano","last_name":"Calcaterra"},{"last_name":"Chrastina","first_name":"Daniel","full_name":"Chrastina, Daniel"},{"full_name":"Isella, Giovanni","last_name":"Isella","first_name":"Giovanni"},{"full_name":"Rimbach-Russ, Maximilian","first_name":"Maximilian","last_name":"Rimbach-Russ"},{"last_name":"Bosco","first_name":"Stefano","full_name":"Bosco, Stefano"},{"id":"38DB5788-F248-11E8-B48F-1D18A9856A87","full_name":"Katsaros, Georgios","first_name":"Georgios","orcid":"0000-0001-8342-202X","last_name":"Katsaros"}],"title":"Exchange anisotropies in microwave-driven singlet-triplet qubits","date_updated":"2026-09-02T22:31:04Z","scopus_import":"1","department":[{"_id":"GeKa"}],"volume":16,"project":[{"_id":"34c0acea-11ca-11ed-8bc3-8775e10fd452","grant_number":"101069515","name":"Integrated Germanium Quantum Technology"},{"_id":"34a66131-11ca-11ed-8bc3-a31681c6b03e","grant_number":"F8606","name":"Center for Correlated Quantum Materials and Solid State Quantum Systems: Conventional  and unconventional topological superconductors"},{"name":"High impedance circuit quantum electrodynamics with hole spins","grant_number":"I05060","_id":"c0977eea-5a5b-11eb-8a69-a862db0cf4d1"},{"name":"Hybrid Semiconductor - Superconductor Quantum Devices","_id":"262116AA-B435-11E9-9278-68D0E5697425"},{"call_identifier":"FWF","_id":"3AC91DDA-15DF-11EA-824D-93A3E7B544D1","name":"FWF Open Access Fund"}],"tmp":{"image":"/images/cc_by.png","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"doi":"10.1038/s41467-025-58969-y","citation":{"ista":"Saez Mollejo J, Jirovec D, Schell YA, Kukucka J, Calcaterra S, Chrastina D, Isella G, Rimbach-Russ M, Bosco S, Katsaros G. 2025. Exchange anisotropies in microwave-driven singlet-triplet qubits. Nature Communications. 16, 3862.","ama":"Saez Mollejo J, Jirovec D, Schell YA, et al. Exchange anisotropies in microwave-driven singlet-triplet qubits. <i>Nature Communications</i>. 2025;16. doi:<a href=\"https://doi.org/10.1038/s41467-025-58969-y\">10.1038/s41467-025-58969-y</a>","apa":"Saez Mollejo, J., Jirovec, D., Schell, Y. A., Kukucka, J., Calcaterra, S., Chrastina, D., … Katsaros, G. (2025). Exchange anisotropies in microwave-driven singlet-triplet qubits. <i>Nature Communications</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41467-025-58969-y\">https://doi.org/10.1038/s41467-025-58969-y</a>","ieee":"J. Saez Mollejo <i>et al.</i>, “Exchange anisotropies in microwave-driven singlet-triplet qubits,” <i>Nature Communications</i>, vol. 16. Springer Nature, 2025.","mla":"Saez Mollejo, Jaime, et al. “Exchange Anisotropies in Microwave-Driven Singlet-Triplet Qubits.” <i>Nature Communications</i>, vol. 16, 3862, Springer Nature, 2025, doi:<a href=\"https://doi.org/10.1038/s41467-025-58969-y\">10.1038/s41467-025-58969-y</a>.","short":"J. Saez Mollejo, D. Jirovec, Y.A. Schell, J. Kukucka, S. Calcaterra, D. Chrastina, G. Isella, M. Rimbach-Russ, S. Bosco, G. Katsaros, Nature Communications 16 (2025).","chicago":"Saez Mollejo, Jaime, Daniel Jirovec, Yona A Schell, Josip Kukucka, Stefano Calcaterra, Daniel Chrastina, Giovanni Isella, Maximilian Rimbach-Russ, Stefano Bosco, and Georgios Katsaros. “Exchange Anisotropies in Microwave-Driven Singlet-Triplet Qubits.” <i>Nature Communications</i>. Springer Nature, 2025. <a href=\"https://doi.org/10.1038/s41467-025-58969-y\">https://doi.org/10.1038/s41467-025-58969-y</a>."},"APC_amount":"7068 EUR","_id":"19424","quality_controlled":"1","oa_version":"Published Version"},{"page":"175","oa":1,"type":"dissertation","file":[{"relation":"source_file","date_created":"2025-06-16T09:38:49Z","creator":"jsaezmol","file_name":"istaustriathesis-master - Copy.zip","checksum":"643bfddead59857536cce4d57c775b32","file_size":59892829,"content_type":"application/x-zip-compressed","access_level":"closed","file_id":"19849","embargo_to":"open_access","date_updated":"2026-04-01T22:30:07Z"},{"date_updated":"2026-04-01T22:30:07Z","embargo":"2026-04-01","file_id":"19851","file_size":22382376,"content_type":"application/pdf","access_level":"open_access","relation":"main_file","date_created":"2025-06-18T08:50:16Z","checksum":"e3dcb767fcc2b1787a455fdda991cefb","creator":"jsaezmol","file_name":"SaezMollejo_PhDFinal_pdfa-1b.pdf"}],"publication_status":"published","year":"2025","article_processing_charge":"No","date_published":"2025-06-13T00:00:00Z","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","publisher":"Institute of Science and Technology Austria","abstract":[{"text":"Over the past century, researchers have been fascinated by the quantum nature of the\r\nphysical world, initially striving to understand its fundamental principles and consequences, and\r\neventually progressing toward engineering systems that can control and manipulate quantum\r\nproperties. Today, we stand at the dawn of the quantum technology era. While some quantum\r\ntechnologies follow well-defined roadmaps, others are still in the exciting and uncertain early\r\nstages of development. In the fields of quantum computing and quantum simulation, research\r\nis being conducted across a wide variety of platforms. Each of these demonstrates control over\r\nquantum properties but also faces challenges in scaling up to the level of a mature technology.\r\nThis thesis explores some of the fundamental properties of hole spin qubits in planar germanium.\r\nSemiconductor spin qubits are considered strong candidates for the realization of quantum\r\nprocessors, owing to their long relaxation and coherence times, as well as their compatibility\r\nwith existing semiconductor industry infrastructure. Among these, hole spin qubits in planar\r\ngermanium are particularly promising. Their advantages include a large effective mass, which\r\neases fabrication constraints; inherent protection from hyperfine noise; and strong spin-orbit\r\ninteraction, which enables fast and purely electrical control. However, spin-orbit coupling also\r\nintroduces site-dependent variability across qubits, particularly in the g-tensors and spin-flip\r\ntunneling, which might cause that the quantization axes are not aligned. In this thesis, we\r\ninvestigate the tilt between the quantization axes of two hole spins hosted in a double quantum\r\ndot as a function of both the magnetic field direction and various electrostatic configurations,\r\ndemonstrating that both parameters influence this tilt. We conclude by introducing a machine-learning-assisted routine to automatically tune baseband spin qubits. This approach may prove\r\nto be a powerful tool for characterizing spin-orbit effects and gaining deeper insight into the\r\nphysics governing spin qubit behavior.\r\n","lang":"eng"}],"has_accepted_license":"1","date_created":"2025-06-13T09:01:50Z","alternative_title":["ISTA Thesis"],"supervisor":[{"id":"38DB5788-F248-11E8-B48F-1D18A9856A87","full_name":"Katsaros, Georgios","first_name":"Georgios","orcid":"0000-0001-8342-202X","last_name":"Katsaros"}],"language":[{"iso":"eng"}],"degree_awarded":"PhD","corr_author":"1","ddc":["530","539"],"month":"06","status":"public","acknowledged_ssus":[{"_id":"NanoFab"},{"_id":"M-Shop"}],"day":"13","file_date_updated":"2026-04-01T22:30:07Z","related_material":{"record":[{"status":"public","relation":"part_of_dissertation","id":"19424"}]},"publication_identifier":{"issn":["2663-337X"]},"acknowledgement":"This research was supported by the Scientific Service Units of ISTA through resources provided\r\nby the MIBA Machine Shop and the Nanofabrication facility. We acknowledge the support from\r\nthe European Commission with the project Integrated Germanium Quantum Technology (with\r\nDOI:10.3030/101069515), the NOMIS Foundation, the HORIZON-RIA 101069515 project and\r\nthe FWF Projects Center for Correlated Quantum Materials and Solid State Quantum Systems:\r\nConventional and unconventional topological superconductors (with DOI:10.55776/F86) and\r\nHigh impedance circuit quantum electrodynamics with hole spins (with DOI:10.55776/I5060).\r\n","OA_place":"publisher","author":[{"full_name":"Saez Mollejo, Jaime","id":"e0390f72-f6e0-11ea-865d-862393336714","last_name":"Saez Mollejo","first_name":"Jaime"}],"title":"Singlet-triplet qubits in planar Germanium: From exchange anisotropies to autonomous tuning ","date_updated":"2026-07-29T12:55:59Z","department":[{"_id":"GradSch"},{"_id":"GeKa"}],"citation":{"apa":"Saez Mollejo, J. (2025). <i>Singlet-triplet qubits in planar Germanium: From exchange anisotropies to autonomous tuning </i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT-ISTA-19836\">https://doi.org/10.15479/AT-ISTA-19836</a>","ista":"Saez Mollejo J. 2025. Singlet-triplet qubits in planar Germanium: From exchange anisotropies to autonomous tuning . Institute of Science and Technology Austria.","ama":"Saez Mollejo J. Singlet-triplet qubits in planar Germanium: From exchange anisotropies to autonomous tuning . 2025. doi:<a href=\"https://doi.org/10.15479/AT-ISTA-19836\">10.15479/AT-ISTA-19836</a>","mla":"Saez Mollejo, Jaime. <i>Singlet-Triplet Qubits in Planar Germanium: From Exchange Anisotropies to Autonomous Tuning </i>. Institute of Science and Technology Austria, 2025, doi:<a href=\"https://doi.org/10.15479/AT-ISTA-19836\">10.15479/AT-ISTA-19836</a>.","ieee":"J. Saez Mollejo, “Singlet-triplet qubits in planar Germanium: From exchange anisotropies to autonomous tuning ,” Institute of Science and Technology Austria, 2025.","short":"J. Saez Mollejo, Singlet-Triplet Qubits in Planar Germanium: From Exchange Anisotropies to Autonomous Tuning , Institute of Science and Technology Austria, 2025.","chicago":"Saez Mollejo, Jaime. “Singlet-Triplet Qubits in Planar Germanium: From Exchange Anisotropies to Autonomous Tuning .” Institute of Science and Technology Austria, 2025. <a href=\"https://doi.org/10.15479/AT-ISTA-19836\">https://doi.org/10.15479/AT-ISTA-19836</a>."},"tmp":{"image":"/images/cc_by.png","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"doi":"10.15479/AT-ISTA-19836","project":[{"_id":"34c0acea-11ca-11ed-8bc3-8775e10fd452","grant_number":"101069515","name":"Integrated Germanium Quantum Technology"},{"_id":"34a66131-11ca-11ed-8bc3-a31681c6b03e","name":"Center for Correlated Quantum Materials and Solid State Quantum Systems: Conventional  and unconventional topological superconductors","grant_number":"F8606"},{"name":"High impedance circuit quantum electrodynamics with hole spins","grant_number":"I05060","_id":"c0977eea-5a5b-11eb-8a69-a862db0cf4d1"}],"oa_version":"Published Version","doi_confirm":"1","_id":"19836"},{"day":"01","acknowledgement":"We thank D. Haviland, J. Pekola, C. Ciuti, A. Bubis and A. Shnirman for helpful feedback on the paper. This research was supported by the Scientific Service Units of IST Austria through resources provided by the MIBA Machine Shop and the Nanofabrication Facility. Work supported by the Austrian FWF grant P33692-N (S.M., J.S. and A.P.H.), the European Union’s Horizon 2020 Research and Innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 754411 (J.S.) and a NOMIS foundation research grant (J.M.F. and A.P.H.).","file_date_updated":"2024-01-29T11:25:38Z","related_material":{"record":[{"relation":"dissertation_contains","id":"17881","status":"public"}]},"publication_identifier":{"issn":["1745-2473"],"eissn":["1745-2481"]},"article_type":"original","external_id":{"isi":["001054563800006"]},"author":[{"full_name":"Mukhopadhyay, Soham","id":"FDE60288-A89D-11E9-947F-1AF6E5697425","first_name":"Soham","last_name":"Mukhopadhyay","orcid":"0000-0001-5263-5559"},{"last_name":"Senior","orcid":"0000-0002-0672-9295","first_name":"Jorden L","full_name":"Senior, Jorden L","id":"5479D234-2D30-11EA-89CC-40953DDC885E"},{"id":"e0390f72-f6e0-11ea-865d-862393336714","full_name":"Saez Mollejo, Jaime","last_name":"Saez Mollejo","first_name":"Jaime"},{"full_name":"Puglia, Denise","id":"4D495994-AE37-11E9-AC72-31CAE5697425","first_name":"Denise","last_name":"Puglia","orcid":"0000-0003-1144-2763"},{"full_name":"Zemlicka, Martin","id":"2DCF8DE6-F248-11E8-B48F-1D18A9856A87","first_name":"Martin","last_name":"Zemlicka","orcid":"0009-0005-0878-3032"},{"full_name":"Fink, Johannes M","id":"4B591CBA-F248-11E8-B48F-1D18A9856A87","first_name":"Johannes M","last_name":"Fink","orcid":"0000-0001-8112-028X"},{"orcid":"0000-0003-2607-2363","last_name":"Higginbotham","first_name":"Andrew P","id":"4AD6785A-F248-11E8-B48F-1D18A9856A87","full_name":"Higginbotham, Andrew P"}],"title":"Superconductivity from a melted insulator in Josephson junction arrays","date_updated":"2026-09-02T22:30:17Z","volume":19,"scopus_import":"1","department":[{"_id":"GradSch"},{"_id":"AnHi"},{"_id":"JoFi"}],"citation":{"ista":"Mukhopadhyay S, Senior JL, Saez Mollejo J, Puglia D, Zemlicka M, Fink JM, Higginbotham AP. 2023. Superconductivity from a melted insulator in Josephson junction arrays. Nature Physics. 19, 1630–1635.","ama":"Mukhopadhyay S, Senior JL, Saez Mollejo J, et al. Superconductivity from a melted insulator in Josephson junction arrays. <i>Nature Physics</i>. 2023;19:1630-1635. doi:<a href=\"https://doi.org/10.1038/s41567-023-02161-w\">10.1038/s41567-023-02161-w</a>","apa":"Mukhopadhyay, S., Senior, J. L., Saez Mollejo, J., Puglia, D., Zemlicka, M., Fink, J. M., &#38; Higginbotham, A. P. (2023). Superconductivity from a melted insulator in Josephson junction arrays. <i>Nature Physics</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41567-023-02161-w\">https://doi.org/10.1038/s41567-023-02161-w</a>","mla":"Mukhopadhyay, Soham, et al. “Superconductivity from a Melted Insulator in Josephson Junction Arrays.” <i>Nature Physics</i>, vol. 19, Springer Nature, 2023, pp. 1630–35, doi:<a href=\"https://doi.org/10.1038/s41567-023-02161-w\">10.1038/s41567-023-02161-w</a>.","ieee":"S. Mukhopadhyay <i>et al.</i>, “Superconductivity from a melted insulator in Josephson junction arrays,” <i>Nature Physics</i>, vol. 19. Springer Nature, pp. 1630–1635, 2023.","short":"S. Mukhopadhyay, J.L. Senior, J. Saez Mollejo, D. Puglia, M. Zemlicka, J.M. Fink, A.P. Higginbotham, Nature Physics 19 (2023) 1630–1635.","chicago":"Mukhopadhyay, Soham, Jorden L Senior, Jaime Saez Mollejo, Denise Puglia, Martin Zemlicka, Johannes M Fink, and Andrew P Higginbotham. “Superconductivity from a Melted Insulator in Josephson Junction Arrays.” <i>Nature Physics</i>. Springer Nature, 2023. <a href=\"https://doi.org/10.1038/s41567-023-02161-w\">https://doi.org/10.1038/s41567-023-02161-w</a>."},"tmp":{"image":"/images/cc_by.png","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"doi":"10.1038/s41567-023-02161-w","project":[{"grant_number":"P33692","name":"Cavity electromechanics across a quantum phase transition","_id":"0aa3608a-070f-11eb-9043-e9cd8a2bd931"},{"call_identifier":"H2020","_id":"260C2330-B435-11E9-9278-68D0E5697425","name":"ISTplus - Postdoctoral Fellowships","grant_number":"754411"},{"name":"Protected states of quantum matter","_id":"eb9b30ac-77a9-11ec-83b8-871f581d53d2"}],"quality_controlled":"1","oa_version":"Published Version","_id":"14032","page":"1630-1635","oa":1,"ec_funded":1,"type":"journal_article","isi":1,"file":[{"creator":"dernst","file_name":"2023_NaturePhysics_Mukhopadhyay.pdf","checksum":"1fc86d71bfbf836e221c1e925343adc5","relation":"main_file","date_created":"2024-01-29T11:25:38Z","content_type":"application/pdf","access_level":"open_access","file_size":1977706,"success":1,"file_id":"14899","date_updated":"2024-01-29T11:25:38Z"}],"publication_status":"published","year":"2023","article_processing_charge":"Yes (in subscription journal)","keyword":["General Physics and Astronomy"],"date_published":"2023-11-01T00:00:00Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publisher":"Springer Nature","has_accepted_license":"1","abstract":[{"text":"Arrays of Josephson junctions are governed by a competition between superconductivity and repulsive Coulomb interactions, and are expected to exhibit diverging low-temperature resistance when interactions exceed a critical level. Here we report a study of the transport and microwave response of Josephson arrays with interactions exceeding this level. Contrary to expectations, we observe that the array resistance drops dramatically as the temperature is decreased—reminiscent of superconducting behaviour—and then saturates at low temperature. Applying a magnetic field, we eventually observe a transition to a highly resistive regime. These observations can be understood within a theoretical picture that accounts for the effect of thermal fluctuations on the insulating phase. On the basis of the agreement between experiment and theory, we suggest that apparent superconductivity in our Josephson arrays arises from melting the zero-temperature insulator.","lang":"eng"}],"date_created":"2023-08-11T07:41:17Z","intvolume":"        19","language":[{"iso":"eng"}],"publication":"Nature Physics","ddc":["530"],"corr_author":"1","month":"11","status":"public","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}]},{"date_updated":"2026-09-02T22:30:43Z","title":"A singlet triplet hole spin qubit in planar Ge","author":[{"id":"4C473F58-F248-11E8-B48F-1D18A9856A87","full_name":"Jirovec, Daniel","orcid":"0000-0002-7197-4801","last_name":"Jirovec","first_name":"Daniel"},{"last_name":"Hofmann","first_name":"Andrea C","full_name":"Hofmann, Andrea C","id":"340F461A-F248-11E8-B48F-1D18A9856A87"},{"full_name":"Ballabio, Andrea","last_name":"Ballabio","first_name":"Andrea"},{"full_name":"Mutter, Philipp M.","first_name":"Philipp M.","last_name":"Mutter"},{"last_name":"Tavani","first_name":"Giulio","full_name":"Tavani, Giulio"},{"full_name":"Botifoll, Marc","first_name":"Marc","last_name":"Botifoll"},{"full_name":"Crippa, Alessandro","id":"1F2B21A2-F6E7-11E9-9B82-F7DBE5697425","last_name":"Crippa","orcid":"0000-0002-2968-611X","first_name":"Alessandro"},{"first_name":"Josip","last_name":"Kukucka","full_name":"Kukucka, Josip","id":"3F5D8856-F248-11E8-B48F-1D18A9856A87"},{"id":"71616374-A8E9-11E9-A7CA-09ECE5697425","full_name":"Sagi, Oliver","last_name":"Sagi","first_name":"Oliver"},{"first_name":"Frederico","last_name":"Martins","orcid":"0000-0003-2668-2401","full_name":"Martins, Frederico","id":"38F80F9A-1CB8-11EA-BC76-B49B3DDC885E"},{"last_name":"Saez Mollejo","first_name":"Jaime","full_name":"Saez Mollejo, Jaime","id":"e0390f72-f6e0-11ea-865d-862393336714"},{"first_name":"Ivan","orcid":"0000-0002-7370-5357","last_name":"Prieto Gonzalez","id":"2A307FE2-F248-11E8-B48F-1D18A9856A87","full_name":"Prieto Gonzalez, Ivan"},{"last_name":"Borovkov","first_name":"Maksim","full_name":"Borovkov, Maksim","id":"2ac7a0a2-3562-11eb-9256-fbd18ea55087"},{"full_name":"Arbiol, Jordi","first_name":"Jordi","last_name":"Arbiol"},{"full_name":"Chrastina, Daniel","last_name":"Chrastina","first_name":"Daniel"},{"full_name":"Isella, Giovanni","last_name":"Isella","first_name":"Giovanni"},{"full_name":"Katsaros, Georgios","id":"38DB5788-F248-11E8-B48F-1D18A9856A87","first_name":"Georgios","last_name":"Katsaros","orcid":"0000-0001-8342-202X"}],"external_id":{"isi":["000657596400001"],"arxiv":["2011.13755"],"pmid":["34083775"]},"arxiv":1,"publication_identifier":{"issn":["1476-1122"],"eissn":["1476-4660"]},"article_type":"original","related_material":{"record":[{"id":"9323","relation":"research_data","status":"public"},{"status":"public","relation":"dissertation_contains","id":"10058"}],"link":[{"relation":"press_release","url":"https://ist.ac.at/en/news/quantum-computing-with-holes/","description":"News on IST Homepage"}]},"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.","day":"01","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/2011.13755"}],"quality_controlled":"1","oa_version":"Preprint","_id":"8909","citation":{"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.","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>","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>."},"doi":"10.1038/s41563-021-01022-2","project":[{"_id":"26A151DA-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","grant_number":"844511","name":"Majorana bound states in Ge/SiGe heterostructures"},{"name":"ISTplus - Postdoctoral Fellowships","grant_number":"754411","call_identifier":"H2020","_id":"260C2330-B435-11E9-9278-68D0E5697425"},{"name":"Hole spin orbit qubits in Ge quantum wells","grant_number":"P30207","call_identifier":"FWF","_id":"2641CE5E-B435-11E9-9278-68D0E5697425"},{"_id":"262116AA-B435-11E9-9278-68D0E5697425","name":"Hybrid Semiconductor - Superconductor Quantum Devices"}],"volume":20,"department":[{"_id":"GeKa"},{"_id":"NanoFab"},{"_id":"GradSch"}],"scopus_import":"1","date_published":"2021-08-01T00:00:00Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_processing_charge":"No","year":"2021","publication_status":"published","oa":1,"isi":1,"ec_funded":1,"type":"journal_article","page":"1106–1112","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"publication":"Nature Materials","status":"public","month":"08","corr_author":"1","issue":"8","intvolume":"        20","language":[{"iso":"eng"}],"publisher":"Springer Nature","abstract":[{"lang":"eng","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."}],"pmid":1,"date_created":"2020-12-02T10:50:47Z"}]