[{"status":"public","OA_type":"hybrid","type":"journal_article","ddc":["530"],"project":[{"_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"}],"title":"Microwave radiometry of a quantum-critical hybrid Josephson array","file":[{"date_updated":"2026-07-16T09:39:37Z","success":1,"relation":"main_file","access_level":"open_access","file_name":"2026_PhysicalReviewApplied_Leonard.pdf","content_type":"application/pdf","date_created":"2026-07-16T09:39:37Z","file_size":2750867,"file_id":"22350","checksum":"d872ca35d9d2c7821642fda520be2c15","creator":"dernst"}],"publication_status":"published","fulldoi":"https://doi.org/10.1103/75bl-mm3b","arxiv":1,"article_processing_charge":"Yes (via OA deal)","has_accepted_license":"1","file_date_updated":"2026-07-16T09:39:37Z","oa":1,"dataavailabilitystatement":"The data that support the findings of this article are openly available under 10.5281/zenodo\r\n.19615009. ","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"supplementarymaterial":"no","PlanS_conform":"1","OA_place":"publisher","corr_author":"1","date_updated":"2026-07-21T12:01:49Z","author":[{"id":"41737c86-5355-11ee-ae5a-d2146bfd0877","first_name":"Kristen W","last_name":"Galvin","full_name":"Galvin, Kristen W"},{"full_name":"Bubis, Anton","id":"1f6212b5-f795-11ec-9c0c-de4780302890","first_name":"Anton","last_name":"Bubis"},{"full_name":"Mikalsen, Melissa","last_name":"Mikalsen","first_name":"Melissa"},{"full_name":"Schiela, William F.","first_name":"William F.","last_name":"Schiela"},{"full_name":"Elfeky, Bassel H.","first_name":"Bassel H.","last_name":"Elfeky"},{"last_name":"Strickland","first_name":"William M.","full_name":"Strickland, William M."},{"last_name":"Phan","first_name":"Duc T","id":"29C8C0B4-F248-11E8-B48F-1D18A9856A87","full_name":"Phan, Duc T"},{"last_name":"Shabani","first_name":"Javad","full_name":"Shabani, Javad"},{"orcid":"0000-0003-2607-2363","full_name":"Higginbotham, Andrew P","last_name":"Higginbotham","first_name":"Andrew P","id":"4AD6785A-F248-11E8-B48F-1D18A9856A87"}],"publication":"Physical Review Applied","year":"2026","date_created":"2026-07-14T05:35:24Z","citation":{"ieee":"K. W. Léonard <i>et al.</i>, “Microwave radiometry of a quantum-critical hybrid Josephson array,” <i>Physical Review Applied</i>, vol. 26. American Physical Society, 2026.","short":"K.W. Léonard, A. Bubis, M. Mikalsen, W.F. Schiela, B.H. Elfeky, W.M. Strickland, D.T. Phan, J. Shabani, A.P. Higginbotham, Physical Review Applied 26 (2026).","mla":"Léonard, Kristen Williams, et al. “Microwave Radiometry of a Quantum-Critical Hybrid Josephson Array.” <i>Physical Review Applied</i>, vol. 26, 014031, American Physical Society, 2026, doi:<a href=\"https://doi.org/10.1103/75bl-mm3b\">10.1103/75bl-mm3b</a>.","chicago":"Léonard, Kristen Williams, Anton Bubis, Melissa Mikalsen, William F. Schiela, Bassel H. Elfeky, William M. Strickland, Duc T Phan, Javad Shabani, and Andrew P Higginbotham. “Microwave Radiometry of a Quantum-Critical Hybrid Josephson Array.” <i>Physical Review Applied</i>. American Physical Society, 2026. <a href=\"https://doi.org/10.1103/75bl-mm3b\">https://doi.org/10.1103/75bl-mm3b</a>.","apa":"Léonard, K. W., Bubis, A., Mikalsen, M., Schiela, W. F., Elfeky, B. H., Strickland, W. M., … Higginbotham, A. P. (2026). Microwave radiometry of a quantum-critical hybrid Josephson array. <i>Physical Review Applied</i>. American Physical Society. <a href=\"https://doi.org/10.1103/75bl-mm3b\">https://doi.org/10.1103/75bl-mm3b</a>","ama":"Léonard KW, Bubis A, Mikalsen M, et al. Microwave radiometry of a quantum-critical hybrid Josephson array. <i>Physical Review Applied</i>. 2026;26. doi:<a href=\"https://doi.org/10.1103/75bl-mm3b\">10.1103/75bl-mm3b</a>","ista":"Léonard KW, Bubis A, Mikalsen M, Schiela WF, Elfeky BH, Strickland WM, Phan DT, Shabani J, Higginbotham AP. 2026. Microwave radiometry of a quantum-critical hybrid Josephson array. Physical Review Applied. 26, 014031."},"doi":"10.1103/75bl-mm3b","day":"10","date_published":"2026-07-10T00:00:00Z","abstract":[{"text":"Arrays of Josephson junctions can be tuned through anomalous metallic, quantum-critical, and insulating regimes. We introduce an alternative experimental probe, capturing microwave radiation across all three regimes, using a two-dimensional array of superconductor-semiconductor hybrid Josephson junctions as a model system. Our approach allows  calibration of the sample’s circuit parameters and provides isolation from measurement back-action effects. We measure the radiation temperature of the anomalous metal and find that it is hotter than both the quantum-critical and insulating regimes. We further show that the anomalous metallic regime is more susceptible to additional heating than other regimes, explaining its emergence in otherwise thermalized systems. Turning to the quantum-critical regime, we discover nonlinear scaling of radiative noise with applied bias, consistent with theoretical predictions of universal nonequilibrium behavior at quantum-critical points.","lang":"eng"}],"scopus_import":"1","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"external_id":{"arxiv":["2409.09835"]},"month":"07","oa_version":"Published Version","publisher":"American Physical Society","_id":"22323","department":[{"_id":"GradSch"},{"_id":"AnHi"},{"_id":"GeKa"}],"acknowledgement":"We gratefully acknowledge feedback on the preprint\r\nfrom Charles Marcus, Vadim Khrapai, Joel Moore,\r\nAndrew Green, Shivaji Sondhi, Rufus Boyack, and\r\nLuca Delacr´etaz. This work was primarily supported by\r\nthe NOMIS foundation. This work was partially supported\r\nby the University of Chicago Materials Research Science\r\nand Engineering Center, which is funded by the National\r\nScience Foundation under Award No. DMR-2011854, and\r\nby the SFB Q-M&S funded by the Austrian Science Fund\r\n(FWF). We acknowledge technical support from the\r\nNanofabrication Facility and the MIBA machine shop at\r\nIST Austria.","article_number":"014031","quality_controlled":"1","researchdata_availability":"yes","volume":26,"publication_identifier":{"issn":["2331-7019"]},"article_type":"original","intvolume":"        26"},{"OA_type":"green","type":"journal_article","status":"public","fulldoi":"https://doi.org/10.1063/5.0333142","arxiv":1,"title":"Low-noise quantum dots in ultra-shallow Ge/SiGe heterostructures for prototyping hybrid semiconducting–superconducting devices","project":[{"grant_number":"101115315","_id":"bdc2ca30-d553-11ed-ba76-cf164a5bb811","name":"Quantum bits with Kitaev Transmons"},{"name":"Center for Correlated Quantum Materials and Solid State Quantum Systems: Conventional  and unconventional topological superconductors","_id":"34a66131-11ca-11ed-8bc3-a31681c6b03e","grant_number":"F8606"},{"grant_number":"PAT 7682124","_id":"5b9e579c-ab3d-11f0-914f-88754c5b5a3f","name":"Superconducting spin qubits in planar Ge"},{"name":"Merging spin and superconducting qubits in planar Ge","grant_number":"P36507","_id":"bd8bd29e-d553-11ed-ba76-f0070d4b237a"},{"name":"Realization and Manipulation of a Planar hybrid superconducting Andreev spin qubit in Germanium","grant_number":"101150858","_id":"8ea8abf7-16d5-11f0-9cad-c41e56ec8bb3"}],"publication_status":"published","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"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.","oa":1,"related_material":{"record":[{"relation":"research_data","status":"public","id":"22242"}]},"article_processing_charge":"No","OA_place":"repository","corr_author":"1","supplementarymaterial":"yes","date_created":"2026-08-02T22:01:53Z","year":"2026","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>.","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>.","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.","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>","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.","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>"},"publication":"Applied Physics Letters","main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.2602.21363"}],"author":[{"first_name":"Maksim","id":"1fd0975f-8b61-11ed-b69e-d149334f28c5","last_name":"Borovkov","full_name":"Borovkov, Maksim"},{"first_name":"Yona A","id":"fe39122d-06bb-11ec-a33b-9e22b40e40a5","last_name":"Schell","full_name":"Schell, Yona A"},{"id":"2d2d62f8-72f0-11ef-b75a-8ec3e8a60032","first_name":"Dina","last_name":"Sokolova","full_name":"Sokolova, Dina"},{"last_name":"Roux","first_name":"Kevin Etienne Robert","id":"53f93ea2-803f-11ed-ab7e-b283135794ef","full_name":"Roux, Kevin Etienne Robert"},{"full_name":"Falthansl-Scheinecker, Paul","id":"85b43b21-15b2-11ec-abd3-e2c252cc2285","first_name":"Paul","last_name":"Falthansl-Scheinecker"},{"full_name":"Fabris, Giorgio","last_name":"Fabris","id":"298cf6f3-1ff6-11ee-9fa6-d94cfa0b3352","first_name":"Giorgio"},{"id":"de191434-4e7e-11ef-bf4b-9a056fc19fc3","first_name":"Devashish C","last_name":"Shah","full_name":"Shah, Devashish C","orcid":"0009-0007-5829-7707"},{"last_name":"Saez Mollejo","id":"e0390f72-f6e0-11ea-865d-862393336714","first_name":"Jaime","full_name":"Saez Mollejo, Jaime"},{"full_name":"Previdi, Rodolfo","last_name":"Previdi","id":"bc4ea1dc-00ce-11ec-8a4e-b325ca8b9876","first_name":"Rodolfo"},{"last_name":"Taha","first_name":"Inas","full_name":"Taha, Inas"},{"full_name":"Genç, Aziz","first_name":"Aziz","last_name":"Genç"},{"first_name":"Jordi","last_name":"Arbiol","full_name":"Arbiol, Jordi"},{"full_name":"Calcaterra, Stefano","last_name":"Calcaterra","first_name":"Stefano"},{"last_name":"Oliveira","first_name":"Afonso De Cerdeira","full_name":"Oliveira, Afonso De Cerdeira"},{"last_name":"Chrastina","first_name":"Daniel","full_name":"Chrastina, Daniel"},{"last_name":"Isella","first_name":"Giovanni","full_name":"Isella, Giovanni"},{"full_name":"Bubis, Anton","id":"1f6212b5-f795-11ec-9c0c-de4780302890","first_name":"Anton","last_name":"Bubis"},{"full_name":"Katsaros, Georgios","orcid":"0000-0001-8342-202X","id":"38DB5788-F248-11E8-B48F-1D18A9856A87","first_name":"Georgios","last_name":"Katsaros"}],"date_updated":"2026-08-03T11:08:39Z","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"das_tickbox":"1","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."}],"scopus_import":"1","doi":"10.1063/5.0333142","date_published":"2026-07-20T00:00:00Z","day":"20","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+).","_id":"22619","department":[{"_id":"GeKa"},{"_id":"GradSch"},{"_id":"NanoFab"}],"month":"07","oa_version":"Preprint","publisher":"AIP Publishing","external_id":{"arxiv":["2602.21363"]},"intvolume":"       129","researchdata_availability":"yes","volume":129,"article_type":"original","publication_identifier":{"issn":["0003-6951"],"eissn":["1077-3118"]},"quality_controlled":"1","issue":"3","article_number":"033505"},{"month":"07","oa_version":"Published Version","publisher":"Institute of Science and Technology Austria","_id":"22242","department":[{"_id":"GradSch"},{"_id":"GeKa"}],"date_updated":"2026-08-03T11:08:38Z","author":[{"full_name":"Borovkov, Maksim","last_name":"Borovkov","first_name":"Maksim","id":"1fd0975f-8b61-11ed-b69e-d149334f28c5"}],"date_created":"2026-07-04T17:32:27Z","year":"2026","citation":{"chicago":"Borovkov, Maksim. “Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping Hybrid Semiconducting-Superconducting Devices.” Institute of Science and Technology Austria, 2026. <a href=\"https://doi.org/10.15479/AT-ISTA-22242\">https://doi.org/10.15479/AT-ISTA-22242</a>.","mla":"Borovkov, Maksim. <i>Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping Hybrid Semiconducting-Superconducting Devices</i>. Institute of Science and Technology Austria, 2026, doi:<a href=\"https://doi.org/10.15479/AT-ISTA-22242\">10.15479/AT-ISTA-22242</a>.","short":"M. Borovkov, (2026).","ieee":"M. Borovkov, “Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping Hybrid Semiconducting-Superconducting Devices.” Institute of Science and Technology Austria, 2026.","ista":"Borovkov M. 2026. Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping Hybrid Semiconducting-Superconducting Devices, Institute of Science and Technology Austria, <a href=\"https://doi.org/10.15479/AT-ISTA-22242\">10.15479/AT-ISTA-22242</a>.","ama":"Borovkov M. Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping Hybrid Semiconducting-Superconducting Devices. 2026. doi:<a href=\"https://doi.org/10.15479/AT-ISTA-22242\">10.15479/AT-ISTA-22242</a>","apa":"Borovkov, M. (2026). Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping Hybrid Semiconducting-Superconducting Devices. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT-ISTA-22242\">https://doi.org/10.15479/AT-ISTA-22242</a>"},"doi":"10.15479/AT-ISTA-22242","date_published":"2026-07-04T00:00:00Z","day":"04","abstract":[{"lang":"eng","text":"This deposit contains the data and analysis code accompanying the publication \"Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping Hybrid Semiconducting–Superconducting Devices\" (Borovkov et al.). The deposit includes the raw transport and current-noise measurements of three gate-defined quantum-dot devices as QCodes SQLite databases, the master table of the charge-noise (flank-method) analysis with the pointers linking every analyzed PSD trace to the raw data, the toy-model noise simulation datasets behind the supplementary figures, the archived analysis figures (PSD fits and lever-arm extractions), and the Python code reproducing the full analysis and all figures. The code is also maintained at https://github.com/ISTA-Nanoelectronics/noise_paper_public; instructions are provided in the README files."}],"acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"file_date_updated":"2026-07-04T17:28:49Z","has_accepted_license":"1","article_processing_charge":"No","oa":1,"related_material":{"link":[{"relation":"research_data","url":"https://github.com/ISTA-Nanoelectronics/noise_paper_public"}],"record":[{"id":"22619","status":"public","relation":"used_in_publication"}]},"user_id":"68b8ca59-c5b3-11ee-8790-cd641c68093d","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"OA_place":"repository","corr_author":"1","status":"public","type":"research_data","ddc":["530"],"contributor":[{"contributor_type":"contact_person","first_name":"Maksim","id":"1fd0975f-8b61-11ed-b69e-d149334f28c5","last_name":"Borovkov"}],"doi_confirm":"1","title":"Low-Noise Quantum Dots in Ultra-Shallow Ge/SiGe Heterostructures for Prototyping Hybrid Semiconducting-Superconducting Devices","project":[{"grant_number":"101115315","_id":"bdc2ca30-d553-11ed-ba76-cf164a5bb811","name":"Quantum bits with Kitaev Transmons"},{"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"},{"name":"Merging spin and superconducting qubits in planar Ge","_id":"bd8bd29e-d553-11ed-ba76-f0070d4b237a","grant_number":"P36507"},{"_id":"8ea8abf7-16d5-11f0-9cad-c41e56ec8bb3","grant_number":"101150858","name":"Realization and Manipulation of a Planar hybrid superconducting Andreev spin qubit in Germanium"},{"name":"Superconducting spin qubits in planar Ge","grant_number":"PAT 7682124","_id":"5b9e579c-ab3d-11f0-914f-88754c5b5a3f"}],"file":[{"file_id":"22243","file_size":3082596099,"checksum":"2a1ea297e01a7a202a6b144d69a46eef","creator":"mborovko","date_updated":"2026-07-04T17:28:49Z","success":1,"relation":"main_file","file_name":"noise_paper_public_deposit.zip","access_level":"open_access","date_created":"2026-07-04T17:28:49Z","content_type":"application/x-zip-compressed"}],"fulldoi":"https://doi.org/10.15479/AT-ISTA-22242"},{"date_created":"2025-03-17T08:57:09Z","year":"2025","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>","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>.","ieee":"J. Saez Mollejo, “Exchange anisotropies in microwave-driven singlet-triplet qubits.” Institute of Science and Technology Austria, 2025.","short":"J. Saez Mollejo, (2025).","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>."},"date_updated":"2026-05-20T06:42:16Z","author":[{"last_name":"Saez Mollejo","id":"e0390f72-f6e0-11ea-865d-862393336714","first_name":"Jaime","full_name":"Saez Mollejo, Jaime"}],"acknowledged_ssus":[{"_id":"NanoFab"},{"_id":"M-Shop"}],"doi":"10.15479/AT:ISTA:19409","date_published":"2025-03-17T00:00:00Z","day":"17","abstract":[{"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","lang":"eng"}],"_id":"19409","department":[{"_id":"GradSch"},{"_id":"GeKa"}],"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.","month":"03","oa_version":"Published Version","publisher":"Institute of Science and Technology Austria","OA_type":"gold","type":"research_data","contributor":[{"orcid":"0000-0002-7197-4801","last_name":"Jirovec","id":"4C473F58-F248-11E8-B48F-1D18A9856A87","first_name":"Daniel"},{"first_name":"Yona A","id":"fe39122d-06bb-11ec-a33b-9e22b40e40a5","last_name":"Schell"},{"last_name":"Kukucka","id":"3F5D8856-F248-11E8-B48F-1D18A9856A87","first_name":"Josip"},{"last_name":"Calcaterra","first_name":"Stefano"},{"first_name":"Daniel ","last_name":"Chrastina"},{"last_name":"Isella","first_name":"Giovanni "},{"last_name":"Rimbach-Russ","first_name":"Maximilian"},{"last_name":"Bosco","first_name":"Stefano"},{"id":"38DB5788-F248-11E8-B48F-1D18A9856A87","first_name":"Georgios","last_name":"Katsaros","orcid":"0000-0001-8342-202X"}],"ddc":["530"],"status":"public","fulldoi":"https://doi.org/10.15479/AT:ISTA:19409","file":[{"file_size":21971911,"file_id":"19410","creator":"jsaezmol","checksum":"1f21c8ea2196776aae51cc3a5d00e00b","success":1,"relation":"main_file","date_updated":"2025-03-17T08:48:09Z","date_created":"2025-03-17T08:48:09Z","content_type":"application/x-zip-compressed","access_level":"open_access","file_name":"AllDataPublished.zip"}],"title":"Exchange anisotropies in microwave-driven singlet-triplet qubits","project":[{"grant_number":"101069515","_id":"34c0acea-11ca-11ed-8bc3-8775e10fd452","name":"Integrated Germanium Quantum Technology"},{"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"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"has_accepted_license":"1","article_processing_charge":"No","file_date_updated":"2025-03-17T08:48:09Z","oa":1,"related_material":{"record":[{"id":"19424","status":"public","relation":"used_in_publication"}]},"OA_place":"publisher","corr_author":"1"},{"status":"public","type":"journal_article","OA_type":"hybrid","APC_amount":"3036,92 EUR","ddc":["530"],"publication_status":"published","title":"Subgap transport in superconductor-semiconductor hybrid islands: Weak and strong coupling regimes","file":[{"date_updated":"2025-04-22T09:00:08Z","success":1,"relation":"main_file","date_created":"2025-04-22T09:00:08Z","content_type":"application/pdf","file_name":"2025_PhysReviewResearch_Valentini.pdf","access_level":"open_access","file_id":"19604","file_size":1977581,"creator":"dernst","checksum":"535351066e9c900340ef014893a09ac8"}],"project":[{"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"}],"fulldoi":"https://doi.org/10.1103/PhysRevResearch.7.023022","article_processing_charge":"Yes","file_date_updated":"2025-04-22T09:00:08Z","has_accepted_license":"1","oa":1,"tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"language":[{"iso":"eng"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","PlanS_conform":"1","corr_author":"1","OA_place":"publisher","date_updated":"2026-06-11T09:13:12Z","author":[{"first_name":"Marco","id":"C0BB2FAC-D767-11E9-B658-BC13E6697425","last_name":"Valentini","full_name":"Valentini, Marco"},{"full_name":"Souto, Rubén Seoane","first_name":"Rubén Seoane","last_name":"Souto"},{"full_name":"Borovkov, Maksim","last_name":"Borovkov","id":"1fd0975f-8b61-11ed-b69e-d149334f28c5","first_name":"Maksim"},{"full_name":"Krogstrup, Peter","first_name":"Peter","last_name":"Krogstrup"},{"first_name":"Yigal","last_name":"Meir","full_name":"Meir, Yigal"},{"full_name":"Leijnse, Martin","first_name":"Martin","last_name":"Leijnse"},{"full_name":"Danon, Jeroen","last_name":"Danon","first_name":"Jeroen"},{"full_name":"Katsaros, Georgios","orcid":"0000-0001-8342-202X","id":"38DB5788-F248-11E8-B48F-1D18A9856A87","first_name":"Georgios","last_name":"Katsaros"}],"publication":"Physical Review Research","citation":{"chicago":"Valentini, Marco, Rubén Seoane Souto, Maksim Borovkov, Peter Krogstrup, Yigal Meir, Martin Leijnse, Jeroen Danon, and Georgios Katsaros. “Subgap Transport in Superconductor-Semiconductor Hybrid Islands: Weak and Strong Coupling Regimes.” <i>Physical Review Research</i>. American Physical Society, 2025. <a href=\"https://doi.org/10.1103/PhysRevResearch.7.023022\">https://doi.org/10.1103/PhysRevResearch.7.023022</a>.","mla":"Valentini, Marco, et al. “Subgap Transport in Superconductor-Semiconductor Hybrid Islands: Weak and Strong Coupling Regimes.” <i>Physical Review Research</i>, vol. 7, no. 2, 023022, American Physical Society, 2025, doi:<a href=\"https://doi.org/10.1103/PhysRevResearch.7.023022\">10.1103/PhysRevResearch.7.023022</a>.","short":"M. Valentini, R.S. Souto, M. Borovkov, P. Krogstrup, Y. Meir, M. Leijnse, J. Danon, G. Katsaros, Physical Review Research 7 (2025).","ieee":"M. Valentini <i>et al.</i>, “Subgap transport in superconductor-semiconductor hybrid islands: Weak and strong coupling regimes,” <i>Physical Review Research</i>, vol. 7, no. 2. American Physical Society, 2025.","ama":"Valentini M, Souto RS, Borovkov M, et al. Subgap transport in superconductor-semiconductor hybrid islands: Weak and strong coupling regimes. <i>Physical Review Research</i>. 2025;7(2). doi:<a href=\"https://doi.org/10.1103/PhysRevResearch.7.023022\">10.1103/PhysRevResearch.7.023022</a>","ista":"Valentini M, Souto RS, Borovkov M, Krogstrup P, Meir Y, Leijnse M, Danon J, Katsaros G. 2025. Subgap transport in superconductor-semiconductor hybrid islands: Weak and strong coupling regimes. Physical Review Research. 7(2), 023022.","apa":"Valentini, M., Souto, R. S., Borovkov, M., Krogstrup, P., Meir, Y., Leijnse, M., … Katsaros, G. (2025). Subgap transport in superconductor-semiconductor hybrid islands: Weak and strong coupling regimes. <i>Physical Review Research</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevResearch.7.023022\">https://doi.org/10.1103/PhysRevResearch.7.023022</a>"},"date_created":"2025-04-20T22:01:28Z","year":"2025","day":"01","DOAJ_listed":"1","date_published":"2025-04-01T00:00:00Z","doi":"10.1103/PhysRevResearch.7.023022","abstract":[{"lang":"eng","text":"Superconductor–semiconductor hybrid systems play a crucial role in realizing nanoscale quantum devices, including hybrid qubits, Majorana bound states, and Kitaev chains. For such hybrid devices, subgap states play a prominent role in their operation. In this paper, we study these subgap states via Coulomb and tunneling spectroscopy through a superconducting island defined in a semiconductor nanowire fully coated by a superconductor. We systematically explore regimes ranging from an almost decoupled island to the open configuration. In the weak-coupling regime, the experimental observations are very similar in the absence of a magnetic field and when one flux quantum pierces the superconducting shell. Conversely, in the strong-coupling regime, significant distinctions emerge between the two cases. We attribute this distinct behavior to the existence of subgap states at one flux quantum, which become observable only for sufficiently strong coupling to the leads. We support our interpretation using a simple model to describe transport through the island. Our study highlights the importance of studying a broad range of tunnel couplings for understanding the rich physics of hybrid devices."}],"scopus_import":"1","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"publisher":"American Physical Society","month":"04","oa_version":"Published Version","department":[{"_id":"GeKa"}],"_id":"19597","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 research and related results were made possible with the support of the FWF Project with DOI10.55776/F86. We acknowledge support from the European Research Council under the European Unions Horizon 2020 research and innovation programme under Grant Agreement No. 856526, the Swedish Research Council under Grant Agreement No. 2020-03412, the Spanish Comunidad de Madrid (CM) “Talento Program” (Project No. 2022-T1/IND-24070), the Spanish Ministry of Science, innovation, and Universities through Grant PID2022-140552NA-I00 and NanoLund.","article_number":"023022","issue":"2","quality_controlled":"1","article_type":"original","publication_identifier":{"issn":["2643-1564"]},"volume":7,"intvolume":"         7"},{"project":[{"name":"Integrated Germanium Quantum Technology","_id":"34c0acea-11ca-11ed-8bc3-8775e10fd452","grant_number":"101069515"},{"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","_id":"34a66131-11ca-11ed-8bc3-a31681c6b03e","grant_number":"F8606"}],"file":[{"checksum":"eff1ae9e46599fdfab8da00a2ca3c289","creator":"jsaezmol","file_size":3404814792,"file_id":"19893","file_name":"DatasetsPaper.zip","access_level":"open_access","date_created":"2025-06-24T15:14:13Z","content_type":"application/x-zip-compressed","success":1,"date_updated":"2025-06-24T15:14:13Z","relation":"main_file"},{"checksum":"21840ceac04d677a799b8e5bd919804f","creator":"jsaezmol","file_id":"19899","file_size":622,"access_level":"open_access","file_name":"README.txt","content_type":"text/plain","date_created":"2025-06-25T07:11:52Z","relation":"main_file","date_updated":"2025-06-25T07:11:52Z","success":1}],"title":"Automated All-RF Tuning for Spin Qubit Readout and Control","fulldoi":"https://doi.org/10.15479/AT:ISTA:19885","status":"public","ddc":["530"],"contributor":[{"last_name":"Carlsson","first_name":"Cornelius","contributor_type":"researcher"},{"contributor_type":"researcher","first_name":"Federico ","last_name":"Fedele"},{"last_name":"Calcaterra","first_name":"Stefano","contributor_type":"researcher"},{"contributor_type":"researcher","first_name":" Daniel ","last_name":"Chrastina"},{"last_name":"Isella","first_name":"Giovanni ","contributor_type":"researcher"},{"last_name":"Katsaros","id":"38DB5788-F248-11E8-B48F-1D18A9856A87","contributor_type":"researcher","first_name":"Georgios","orcid":"0000-0001-8342-202X"},{"last_name":"Ares","first_name":"Natalia","contributor_type":"researcher"}],"type":"research_data","corr_author":"1","oa":1,"file_date_updated":"2025-06-25T07:11:52Z","article_processing_charge":"No","has_accepted_license":"1","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","abstract":[{"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.","lang":"eng"}],"day":"01","date_published":"2025-06-01T00:00:00Z","doi":"10.15479/AT:ISTA:19885","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"author":[{"full_name":"Saez Mollejo, Jaime","id":"e0390f72-f6e0-11ea-865d-862393336714","first_name":"Jaime","last_name":"Saez Mollejo"}],"date_updated":"2025-07-01T07:19:26Z","citation":{"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>.","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>","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).","ieee":"J. Saez Mollejo, “Automated All-RF Tuning for Spin Qubit Readout and Control.” Institute of Science and Technology Austria, 2025.","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>."},"year":"2025","date_created":"2025-06-24T06:56:03Z","publisher":"Institute of Science and Technology Austria","month":"06","oa_version":"Published Version","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).","department":[{"_id":"GradSch"},{"_id":"GeKa"}],"_id":"19885"},{"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.","_id":"19424","department":[{"_id":"GeKa"}],"month":"04","oa_version":"Published Version","publisher":"Springer Nature","external_id":{"isi":["001475587400022"],"arxiv":["2408.03224"],"pmid":["40274808"]},"intvolume":"        16","volume":16,"article_type":"original","publication_identifier":{"eissn":["2041-1723"]},"quality_controlled":"1","article_number":"3862","pmid":1,"date_created":"2025-03-19T13:28:12Z","year":"2025","citation":{"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>","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.","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>","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>.","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).","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>."},"publication":"Nature Communications","author":[{"id":"e0390f72-f6e0-11ea-865d-862393336714","first_name":"Jaime","last_name":"Saez Mollejo","full_name":"Saez Mollejo, Jaime"},{"first_name":"Daniel","id":"4C473F58-F248-11E8-B48F-1D18A9856A87","last_name":"Jirovec","full_name":"Jirovec, Daniel","orcid":"0000-0002-7197-4801"},{"full_name":"Schell, Yona A","first_name":"Yona A","id":"fe39122d-06bb-11ec-a33b-9e22b40e40a5","last_name":"Schell"},{"first_name":"Josip","id":"3F5D8856-F248-11E8-B48F-1D18A9856A87","last_name":"Kukucka","full_name":"Kukucka, Josip"},{"full_name":"Calcaterra, Stefano","first_name":"Stefano","last_name":"Calcaterra"},{"full_name":"Chrastina, Daniel","last_name":"Chrastina","first_name":"Daniel"},{"last_name":"Isella","first_name":"Giovanni","full_name":"Isella, Giovanni"},{"full_name":"Rimbach-Russ, Maximilian","last_name":"Rimbach-Russ","first_name":"Maximilian"},{"full_name":"Bosco, Stefano","last_name":"Bosco","first_name":"Stefano"},{"last_name":"Katsaros","id":"38DB5788-F248-11E8-B48F-1D18A9856A87","first_name":"Georgios","orcid":"0000-0001-8342-202X","full_name":"Katsaros, Georgios"}],"date_updated":"2026-10-20T22:31:01Z","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"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."}],"scopus_import":"1","doi":"10.1038/s41467-025-58969-y","day":"24","date_published":"2025-04-24T00:00:00Z","DOAJ_listed":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"oa":1,"related_material":{"link":[{"relation":"research_data","url":"https://ista.ac.at/en/news/the-shadow-of-an-electron/","description":"News on ISTA website"}],"record":[{"relation":"research_data","id":"19409","status":"public"},{"relation":"dissertation_contains","status":"public","id":"19836"}]},"article_processing_charge":"Yes","has_accepted_license":"1","file_date_updated":"2025-05-05T07:08:23Z","OA_place":"publisher","corr_author":"1","ddc":["530"],"OA_type":"gold","APC_amount":"7068 EUR","type":"journal_article","status":"public","isi":1,"fulldoi":"https://doi.org/10.1038/s41467-025-58969-y","arxiv":1,"project":[{"name":"Integrated Germanium Quantum Technology","grant_number":"101069515","_id":"34c0acea-11ca-11ed-8bc3-8775e10fd452"},{"grant_number":"F8606","_id":"34a66131-11ca-11ed-8bc3-a31681c6b03e","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"},{"_id":"262116AA-B435-11E9-9278-68D0E5697425","name":"Hybrid Semiconductor - Superconductor Quantum Devices"},{"call_identifier":"FWF","name":"FWF Open Access Fund","_id":"3AC91DDA-15DF-11EA-824D-93A3E7B544D1"}],"file":[{"creator":"dernst","checksum":"13fe84cddc9d4e47213bf17acdac70d7","file_size":1548756,"file_id":"19645","content_type":"application/pdf","date_created":"2025-05-05T07:08:23Z","access_level":"open_access","file_name":"2025_NatureComm_SaezMollejo.pdf","relation":"main_file","success":1,"date_updated":"2025-05-05T07:08:23Z"}],"title":"Exchange anisotropies in microwave-driven singlet-triplet qubits","publication_status":"published"},{"type":"dissertation","degree_awarded":"PhD","ddc":["530","539"],"status":"public","fulldoi":"https://doi.org/10.15479/AT-ISTA-19836","doi_confirm":"1","publication_status":"published","title":"Singlet-triplet qubits in planar Germanium: From exchange anisotropies to autonomous tuning ","file":[{"access_level":"closed","file_name":"istaustriathesis-master - Copy.zip","content_type":"application/x-zip-compressed","date_created":"2025-06-16T09:38:49Z","embargo_to":"open_access","relation":"source_file","date_updated":"2026-04-01T22:30:07Z","checksum":"643bfddead59857536cce4d57c775b32","creator":"jsaezmol","file_size":59892829,"file_id":"19849"},{"file_name":"SaezMollejo_PhDFinal_pdfa-1b.pdf","access_level":"open_access","embargo":"2026-04-01","date_created":"2025-06-18T08:50:16Z","content_type":"application/pdf","date_updated":"2026-04-01T22:30:07Z","relation":"main_file","checksum":"e3dcb767fcc2b1787a455fdda991cefb","creator":"jsaezmol","file_id":"19851","file_size":22382376}],"project":[{"name":"Integrated Germanium Quantum Technology","_id":"34c0acea-11ca-11ed-8bc3-8775e10fd452","grant_number":"101069515"},{"_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":"c0977eea-5a5b-11eb-8a69-a862db0cf4d1","grant_number":"I05060","name":"High impedance circuit quantum electrodynamics with hole spins"}],"language":[{"iso":"eng"}],"tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"page":"175","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","article_processing_charge":"No","file_date_updated":"2026-04-01T22:30:07Z","has_accepted_license":"1","related_material":{"record":[{"relation":"part_of_dissertation","id":"19424","status":"public"}]},"oa":1,"corr_author":"1","OA_place":"publisher","supervisor":[{"orcid":"0000-0001-8342-202X","full_name":"Katsaros, Georgios","last_name":"Katsaros","first_name":"Georgios","id":"38DB5788-F248-11E8-B48F-1D18A9856A87"}],"citation":{"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>","ista":"Saez Mollejo J. 2025. Singlet-triplet qubits in planar Germanium: From exchange anisotropies to autonomous tuning . Institute of Science and Technology Austria.","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>","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>.","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.","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>."},"year":"2025","date_created":"2025-06-13T09:01:50Z","date_updated":"2026-07-29T12:55:59Z","author":[{"last_name":"Saez Mollejo","id":"e0390f72-f6e0-11ea-865d-862393336714","first_name":"Jaime","full_name":"Saez Mollejo, Jaime"}],"acknowledged_ssus":[{"_id":"NanoFab"},{"_id":"M-Shop"}],"day":"13","date_published":"2025-06-13T00:00:00Z","doi":"10.15479/AT-ISTA-19836","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"}],"department":[{"_id":"GradSch"},{"_id":"GeKa"}],"alternative_title":["ISTA Thesis"],"_id":"19836","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","publisher":"Institute of Science and Technology Austria","oa_version":"Published Version","month":"06","publication_identifier":{"issn":["2663-337X"]}},{"das_tickbox":"1","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"day":"02","DOAJ_listed":"1","date_published":"2024-01-02T00:00:00Z","doi":"10.1038/s41467-023-44114-0","scopus_import":"1","abstract":[{"lang":"eng","text":"Superconductor/semiconductor hybrid devices have attracted increasing interest in the past years. Superconducting electronics aims to complement semiconductor technology, while hybrid architectures are at the forefront of new ideas such as topological superconductivity and protected qubits. In this work, we engineer the induced superconductivity in two-dimensional germanium hole gas by varying the distance between the quantum well and the aluminum. We demonstrate a hard superconducting gap and realize an electrically and flux tunable superconducting diode using a superconducting quantum interference device (SQUID). This allows to tune the current phase relation (CPR), to a regime where single Cooper pair tunneling is suppressed, creating a sin(2y) CPR. Shapiro experiments complement this interpretation and the microwave drive allows to create a diode with ≈ 100% efficiency. The reported results open up the path towards integration of spin qubit devices, microwave resonators and (protected) superconducting qubits on  the same silicon technology compatible platform."}],"publication":"Nature Communications","citation":{"ista":"Valentini M, Sagi O, Baghumyan L, de Gijsel T, Jung J, Calcaterra S, Ballabio A, Aguilera Servin JL, Aggarwal K, Janik M, Adletzberger T, Seoane Souto R, Leijnse M, Danon J, Schrade C, Bakkers E, Chrastina D, Isella G, Katsaros G. 2024. Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium. Nature Communications. 15, 169.","ama":"Valentini M, Sagi O, Baghumyan L, et al. Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium. <i>Nature Communications</i>. 2024;15. doi:<a href=\"https://doi.org/10.1038/s41467-023-44114-0\">10.1038/s41467-023-44114-0</a>","apa":"Valentini, M., Sagi, O., Baghumyan, L., de Gijsel, T., Jung, J., Calcaterra, S., … Katsaros, G. (2024). Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium. <i>Nature Communications</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41467-023-44114-0\">https://doi.org/10.1038/s41467-023-44114-0</a>","chicago":"Valentini, Marco, Oliver Sagi, Levon Baghumyan, Thijs de Gijsel, Jason Jung, Stefano Calcaterra, Andrea Ballabio, et al. “Parity-Conserving Cooper-Pair Transport and Ideal Superconducting Diode in Planar Germanium.” <i>Nature Communications</i>. Springer Nature, 2024. <a href=\"https://doi.org/10.1038/s41467-023-44114-0\">https://doi.org/10.1038/s41467-023-44114-0</a>.","mla":"Valentini, Marco, et al. “Parity-Conserving Cooper-Pair Transport and Ideal Superconducting Diode in Planar Germanium.” <i>Nature Communications</i>, vol. 15, 169, Springer Nature, 2024, doi:<a href=\"https://doi.org/10.1038/s41467-023-44114-0\">10.1038/s41467-023-44114-0</a>.","short":"M. Valentini, O. Sagi, L. Baghumyan, T. de Gijsel, J. Jung, S. Calcaterra, A. Ballabio, J.L. Aguilera Servin, K. Aggarwal, M. Janik, T. Adletzberger, R. Seoane Souto, M. Leijnse, J. Danon, C. Schrade, E. Bakkers, D. Chrastina, G. Isella, G. Katsaros, Nature Communications 15 (2024).","ieee":"M. Valentini <i>et al.</i>, “Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium,” <i>Nature Communications</i>, vol. 15. Springer Nature, 2024."},"date_created":"2024-01-14T23:00:56Z","year":"2024","date_updated":"2026-10-02T10:23:53Z","author":[{"last_name":"Valentini","id":"C0BB2FAC-D767-11E9-B658-BC13E6697425","first_name":"Marco","full_name":"Valentini, Marco"},{"full_name":"Sagi, Oliver","last_name":"Sagi","id":"71616374-A8E9-11E9-A7CA-09ECE5697425","first_name":"Oliver"},{"full_name":"Baghumyan, Levon","last_name":"Baghumyan","first_name":"Levon","id":"7aa1f788-b527-11ee-aa9e-e6111a79e0c7"},{"full_name":"de Gijsel, Thijs","id":"a0ece13c-b527-11ee-929d-bad130106eee","first_name":"Thijs","last_name":"de Gijsel"},{"id":"4C9ACE7A-F248-11E8-B48F-1D18A9856A87","first_name":"Jason","last_name":"Jung","full_name":"Jung, Jason"},{"last_name":"Calcaterra","first_name":"Stefano","full_name":"Calcaterra, Stefano"},{"full_name":"Ballabio, Andrea","first_name":"Andrea","last_name":"Ballabio"},{"first_name":"Juan L","id":"2A67C376-F248-11E8-B48F-1D18A9856A87","last_name":"Aguilera Servin","full_name":"Aguilera Servin, Juan L","orcid":"0000-0002-2862-8372"},{"last_name":"Aggarwal","id":"b22ab905-3539-11eb-84c3-fc159dcd79cb","first_name":"Kushagra","orcid":"0000-0001-9985-9293","full_name":"Aggarwal, Kushagra"},{"first_name":"Marian","id":"396A1950-F248-11E8-B48F-1D18A9856A87","last_name":"Janik","full_name":"Janik, Marian","orcid":"0009-0003-9037-8831"},{"full_name":"Adletzberger, Thomas","id":"38756BB2-F248-11E8-B48F-1D18A9856A87","first_name":"Thomas","last_name":"Adletzberger"},{"last_name":"Seoane Souto","first_name":"Rubén","full_name":"Seoane Souto, Rubén"},{"full_name":"Leijnse, Martin","first_name":"Martin","last_name":"Leijnse"},{"full_name":"Danon, Jeroen","first_name":"Jeroen","last_name":"Danon"},{"full_name":"Schrade, Constantin","last_name":"Schrade","first_name":"Constantin"},{"full_name":"Bakkers, Erik","first_name":"Erik","last_name":"Bakkers"},{"last_name":"Chrastina","first_name":"Daniel","full_name":"Chrastina, Daniel"},{"first_name":"Giovanni","last_name":"Isella","full_name":"Isella, Giovanni"},{"orcid":"0000-0001-8342-202X","full_name":"Katsaros, Georgios","last_name":"Katsaros","first_name":"Georgios","id":"38DB5788-F248-11E8-B48F-1D18A9856A87"}],"publication_identifier":{"eissn":["2041-1723"]},"article_type":"original","volume":15,"researchdata_availability":"yes","intvolume":"        15","pmid":1,"article_number":"169","quality_controlled":"1","department":[{"_id":"GeKa"}],"_id":"14793","acknowledgement":"We acknowledge Alexander Brinkmann, Alessandro Crippa, Francesco Giazotto, Andrew Higginbotham, Andrea Iorio, Giordano Scappucci, Christian Schonenberger, and Lukas Splitthoff for helpful discussions. We thank Marcel Verheijen for the support in the TEM analysis. This research and related results were made possible with the support of the NOMIS\r\nFoundation. It was supported by the Scientific Service Units of ISTA through resources provided by the MIBA Machine Shop and the nanofabrication facility, the European Union’s Horizon 2020 research andinnovation programme under Grant Agreement No 862046, the HORIZONRIA\r\n101069515 project, the European Innovation Council Pathfinder grant no. 101115315 (QuKiT), and the FWF Projects #P-32235, #P-36507 and #F-8606. For the purpose of open access, the authors have applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. R.S.S. acknowledges Spanish CM “Talento Program\"\r\nProject No. 2022-T1/IND-24070. J.J. acknowledges European Research Council TOCINA 834290.","external_id":{"pmid":["38167818"],"isi":["001142794000839"]},"publisher":"Springer Nature","oa_version":"Published Version","month":"01","fulldoi":"https://doi.org/10.1038/s41467-023-44114-0","isi":1,"publication_status":"published","file":[{"creator":"dernst","checksum":"ef79173b45eeaf984ffa61ef2f8a52ab","file_size":2336595,"file_id":"14825","content_type":"application/pdf","date_created":"2024-01-17T11:03:00Z","access_level":"open_access","file_name":"2024_NatureComm_Valentini.pdf","relation":"main_file","date_updated":"2024-01-17T11:03:00Z","success":1}],"title":"Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium","project":[{"name":"TOPOLOGICALLY PROTECTED AND SCALABLE QUANTUM BITS","_id":"237E5020-32DE-11EA-91FC-C7463DDC885E","grant_number":"862046","call_identifier":"H2020"},{"name":"Integrated Germanium Quantum Technology","_id":"34c0acea-11ca-11ed-8bc3-8775e10fd452","grant_number":"101069515"},{"grant_number":"101115315","_id":"bdc2ca30-d553-11ed-ba76-cf164a5bb811","name":"Quantum bits with Kitaev Transmons"},{"name":"Towards scalable hut wire quantum devices","_id":"237B3DA4-32DE-11EA-91FC-C7463DDC885E","grant_number":"P32235","call_identifier":"FWF"},{"_id":"bd8bd29e-d553-11ed-ba76-f0070d4b237a","grant_number":"P36507","name":"Merging spin and superconducting qubits in planar Ge"},{"_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":"FWF Open Access Fund","_id":"3AC91DDA-15DF-11EA-824D-93A3E7B544D1","call_identifier":"FWF"}],"type":"journal_article","APC_amount":"6468 EUR","OA_type":"gold","ec_funded":1,"ddc":["530"],"status":"public","corr_author":"1","OA_place":"publisher","supplementarymaterial":"yes","dataavailabilitystatement":"All experimental data included in this work are available at https://zenodo.org/records/10119346.","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"language":[{"iso":"eng"}],"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","file_date_updated":"2024-01-17T11:03:00Z","has_accepted_license":"1","article_processing_charge":"Yes","related_material":{"record":[{"status":"public","id":"13312","relation":"earlier_version"},{"status":"public","id":"23036","relation":"research_data"}]},"oa":1},{"_id":"13286","alternative_title":["ISTA Thesis"],"department":[{"_id":"GradSch"},{"_id":"GeKa"}],"month":"07","oa_version":"Published Version","publisher":"Institute of Science and Technology Austria","publication_identifier":{"issn":["2663-337X"]},"supervisor":[{"id":"38DB5788-F248-11E8-B48F-1D18A9856A87","first_name":"Georgios","last_name":"Katsaros","full_name":"Katsaros, Georgios","orcid":"0000-0001-8342-202X"}],"date_created":"2023-07-24T14:10:45Z","year":"2023","citation":{"chicago":"Valentini, Marco. “Mesoscopic Phenomena in Hybrid Semiconductor-Superconductor Nanodevices : From Full-Shell Nanowires to Two-Dimensional Hole Gas in Germanium.” Institute of Science and Technology Austria, 2023. <a href=\"https://doi.org/10.15479/at:ista:13286\">https://doi.org/10.15479/at:ista:13286</a>.","mla":"Valentini, Marco. <i>Mesoscopic Phenomena in Hybrid Semiconductor-Superconductor Nanodevices : From Full-Shell Nanowires to Two-Dimensional Hole Gas in Germanium</i>. Institute of Science and Technology Austria, 2023, doi:<a href=\"https://doi.org/10.15479/at:ista:13286\">10.15479/at:ista:13286</a>.","short":"M. Valentini, Mesoscopic Phenomena in Hybrid Semiconductor-Superconductor Nanodevices : From Full-Shell Nanowires to Two-Dimensional Hole Gas in Germanium, Institute of Science and Technology Austria, 2023.","ieee":"M. Valentini, “Mesoscopic phenomena in hybrid semiconductor-superconductor nanodevices : From full-shell nanowires to two-dimensional hole gas in germanium,” Institute of Science and Technology Austria, 2023.","ama":"Valentini M. Mesoscopic phenomena in hybrid semiconductor-superconductor nanodevices : From full-shell nanowires to two-dimensional hole gas in germanium. 2023. doi:<a href=\"https://doi.org/10.15479/at:ista:13286\">10.15479/at:ista:13286</a>","ista":"Valentini M. 2023. Mesoscopic phenomena in hybrid semiconductor-superconductor nanodevices : From full-shell nanowires to two-dimensional hole gas in germanium. Institute of Science and Technology Austria.","apa":"Valentini, M. (2023). <i>Mesoscopic phenomena in hybrid semiconductor-superconductor nanodevices : From full-shell nanowires to two-dimensional hole gas in germanium</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:13286\">https://doi.org/10.15479/at:ista:13286</a>"},"date_updated":"2026-06-03T07:16:01Z","author":[{"last_name":"Valentini","first_name":"Marco","id":"C0BB2FAC-D767-11E9-B658-BC13E6697425","full_name":"Valentini, Marco"}],"acknowledged_ssus":[{"_id":"NanoFab"},{"_id":"M-Shop"}],"doi":"10.15479/at:ista:13286","day":"21","date_published":"2023-07-21T00:00:00Z","abstract":[{"lang":"eng","text":"Semiconductor-superconductor hybrid systems are the harbour of many intriguing mesoscopic phenomena. This material combination leads to spatial variations of the superconducting properties, which gives rise to Andreev bound states (ABSs). Some of these states might exhibit remarkable properties that render them highly desirable for topological quantum computing. The most prominent and hunted of such states are Majorana zero modes (MZMs), quasiparticles equals to their own quasiparticles that they follow non-abelian statistics. In this thesis, we first introduce the general framework of such hybrid systems and, then, we unveil a series of mesoscopic phenomena that we discovered. Firstly, we show tunneling spectroscopy experiments on full-shell nanowires (NWs) showing that unwanted quantum-dot states coupled to superconductors (Yu-Shiba-Rusinov states) can mimic MZMs signatures. Then, we introduce a novel protocol which allowed the integration of tunneling spectroscopy with Coulomb spectroscopy within the same device. Employing this approach on both full-shell NWs and partial-shell NWs, we demonstrated that longitudinally confined states reveal charge transport phenomenology similar to the one expected for MZMs. These findings shed light on the intricate interplay between superconductivity and quantum confinement, which brought us to explore another material platform, i.e. a two-dimensional Germanium hole gas. After developing a robust way to induce superconductivity in such system, we showed how to engineer the proximity effect and we revealed a superconducting hard gap. Finally, we created a superconducting radio frequency driven ideal diode and a generator of non-sinusoidal current-phase relations. Our results open the path for the exploration of protected superconducting qubits and more complex hybrid devices in planar Germanium, like Kitaev chains and hybrid qubit devices."}],"page":"184","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","language":[{"iso":"eng"}],"tmp":{"name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","image":"/images/cc_by_nc_sa.png","short":"CC BY-NC-SA (4.0)"},"has_accepted_license":"1","article_processing_charge":"No","file_date_updated":"2023-08-11T14:39:17Z","oa":1,"related_material":{"record":[{"relation":"research_data","id":"12522","status":"public"},{"relation":"part_of_dissertation","id":"12118","status":"public"},{"status":"public","id":"8910","relation":"part_of_dissertation"},{"relation":"part_of_dissertation","id":"13312","status":"public"}]},"OA_place":"publisher","corr_author":"1","type":"dissertation","ec_funded":1,"ddc":["530"],"degree_awarded":"PhD","status":"public","fulldoi":"https://doi.org/10.15479/at:ista:13286","project":[{"_id":"262116AA-B435-11E9-9278-68D0E5697425","name":"Hybrid Semiconductor - Superconductor Quantum Devices"},{"name":"TOPOLOGICALLY PROTECTED AND SCALABLE QUANTUM BITS","grant_number":"862046","_id":"237E5020-32DE-11EA-91FC-C7463DDC885E","call_identifier":"H2020"},{"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"}],"file":[{"file_size":56121429,"file_id":"14033","creator":"mvalenti","checksum":"666ee31c7eade89679806287c062fa14","date_updated":"2023-08-11T10:01:34Z","relation":"source_file","content_type":"application/x-zip-compressed","date_created":"2023-08-11T09:27:39Z","access_level":"closed","file_name":"PhD_thesis_Valentini_final.zip"},{"file_size":38199711,"file_id":"14035","checksum":"0992f2ebef152dee8e70055350ebbb55","creator":"mvalenti","date_updated":"2023-08-11T14:39:17Z","relation":"main_file","access_level":"open_access","file_name":"PhD_thesis_Valentini_final_validated.pdf","content_type":"application/pdf","date_created":"2023-08-11T14:39:17Z"}],"title":"Mesoscopic phenomena in hybrid semiconductor-superconductor nanodevices : From full-shell nanowires to two-dimensional hole gas in germanium","publication_status":"published"},{"article_number":"2306.07109","department":[{"_id":"GeKa"},{"_id":"M-Shop"}],"_id":"13312","acknowledgement":"The authors acknowledge Alexander Brinkmann, Alessandro Crippa, Andrew Higginbotham, Andrea Iorio, Giordano\r\nScappucci and Christian Schonenberger for helpful discussions. We thank Marcel Verheijen for the support in the\r\nTEM analysis. This research and related results were made\r\npossible with the support of the NOMIS Foundation. It was\r\nsupported by the Scientific Service Units of ISTA through resources provided by the MIBA Machine Shop and the\r\nnanofabrication facility, the European Union’s Horizon 2020\r\nresearch and innovation programme under Grant Agreement\r\nNo 862046, the HORIZON-RIA 101069515 project and the\r\nFWF Projects #P-32235, #P-36507 and #F-8606. R.S.S.\r\nacknowledges Spanish CM “Talento Program” Project No.\r\n2022-T1/IND-24070.","external_id":{"arxiv":["2306.07109"]},"month":"06","oa_version":"Preprint","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"day":"13","date_published":"2023-06-13T00:00:00Z","doi":"10.48550/arXiv.2306.07109","abstract":[{"text":"Superconductor/semiconductor hybrid devices have attracted increasing\r\ninterest in the past years. Superconducting electronics aims to complement\r\nsemiconductor technology, while hybrid architectures are at the forefront of\r\nnew ideas such as topological superconductivity and protected qubits. In this\r\nwork, we engineer the induced superconductivity in two-dimensional germanium\r\nhole gas by varying the distance between the quantum well and the aluminum. We\r\ndemonstrate a hard superconducting gap and realize an electrically and flux\r\ntunable superconducting diode using a superconducting quantum interference\r\ndevice (SQUID). This allows to tune the current phase relation (CPR), to a\r\nregime where single Cooper pair tunneling is suppressed, creating a $ \\sin\r\n\\left( 2 \\varphi \\right)$ CPR. Shapiro experiments complement this\r\ninterpretation and the microwave drive allows to create a diode with $ \\approx\r\n100 \\%$ efficiency. The reported results open up the path towards monolithic\r\nintegration of spin qubit devices, microwave resonators and (protected)\r\nsuperconducting qubits on a silicon technology compatible platform.","lang":"eng"}],"publication":"arXiv","main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.2306.07109"}],"citation":{"mla":"Valentini, Marco, et al. “Radio Frequency Driven Superconducting Diode and Parity Conserving  Cooper Pair Transport in a Two-Dimensional Germanium Hole Gas.” <i>ArXiv</i>, 2306.07109, doi:<a href=\"https://doi.org/10.48550/arXiv.2306.07109\">10.48550/arXiv.2306.07109</a>.","short":"M. Valentini, O. Sagi, L. Baghumyan, T. de Gijsel, J. Jung, S. Calcaterra, A. Ballabio, J.A. Servin, K. Aggarwal, M. Janik, T. Adletzberger, R.S. Souto, M. Leijnse, J. Danon, C. Schrade, E. Bakkers, D. Chrastina, G. Isella, G. Katsaros, ArXiv (n.d.).","ieee":"M. Valentini <i>et al.</i>, “Radio frequency driven superconducting diode and parity conserving  Cooper pair transport in a two-dimensional germanium hole gas,” <i>arXiv</i>. .","chicago":"Valentini, Marco, Oliver Sagi, Levon Baghumyan, Thijs de Gijsel, Jason Jung, Stefano Calcaterra, Andrea Ballabio, et al. “Radio Frequency Driven Superconducting Diode and Parity Conserving  Cooper Pair Transport in a Two-Dimensional Germanium Hole Gas.” <i>ArXiv</i>, n.d. <a href=\"https://doi.org/10.48550/arXiv.2306.07109\">https://doi.org/10.48550/arXiv.2306.07109</a>.","apa":"Valentini, M., Sagi, O., Baghumyan, L., Gijsel, T. de, Jung, J., Calcaterra, S., … Katsaros, G. (n.d.). Radio frequency driven superconducting diode and parity conserving  Cooper pair transport in a two-dimensional germanium hole gas. <i>arXiv</i>. <a href=\"https://doi.org/10.48550/arXiv.2306.07109\">https://doi.org/10.48550/arXiv.2306.07109</a>","ista":"Valentini M, Sagi O, Baghumyan L, Gijsel T de, Jung J, Calcaterra S, Ballabio A, Servin JA, Aggarwal K, Janik M, Adletzberger T, Souto RS, Leijnse M, Danon J, Schrade C, Bakkers E, Chrastina D, Isella G, Katsaros G. Radio frequency driven superconducting diode and parity conserving  Cooper pair transport in a two-dimensional germanium hole gas. arXiv, 2306.07109.","ama":"Valentini M, Sagi O, Baghumyan L, et al. Radio frequency driven superconducting diode and parity conserving  Cooper pair transport in a two-dimensional germanium hole gas. <i>arXiv</i>. doi:<a href=\"https://doi.org/10.48550/arXiv.2306.07109\">10.48550/arXiv.2306.07109</a>"},"year":"2023","date_created":"2023-07-26T11:17:20Z","date_updated":"2026-10-02T10:23:31Z","author":[{"full_name":"Valentini, Marco","last_name":"Valentini","first_name":"Marco","id":"C0BB2FAC-D767-11E9-B658-BC13E6697425"},{"last_name":"Sagi","id":"71616374-A8E9-11E9-A7CA-09ECE5697425","first_name":"Oliver","full_name":"Sagi, Oliver"},{"first_name":"Levon","last_name":"Baghumyan","full_name":"Baghumyan, Levon"},{"full_name":"Gijsel, Thijs de","first_name":"Thijs de","last_name":"Gijsel"},{"full_name":"Jung, Jason","last_name":"Jung","first_name":"Jason","id":"4C9ACE7A-F248-11E8-B48F-1D18A9856A87"},{"full_name":"Calcaterra, Stefano","first_name":"Stefano","last_name":"Calcaterra"},{"last_name":"Ballabio","first_name":"Andrea","full_name":"Ballabio, Andrea"},{"full_name":"Servin, Juan Aguilera","first_name":"Juan Aguilera","last_name":"Servin"},{"full_name":"Aggarwal, Kushagra","orcid":"0000-0001-9985-9293","first_name":"Kushagra","id":"b22ab905-3539-11eb-84c3-fc159dcd79cb","last_name":"Aggarwal"},{"last_name":"Janik","first_name":"Marian","id":"396A1950-F248-11E8-B48F-1D18A9856A87","orcid":"0009-0003-9037-8831","full_name":"Janik, Marian"},{"full_name":"Adletzberger, Thomas","last_name":"Adletzberger","first_name":"Thomas","id":"38756BB2-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Souto","first_name":"Rubén Seoane","full_name":"Souto, Rubén Seoane"},{"full_name":"Leijnse, Martin","first_name":"Martin","last_name":"Leijnse"},{"full_name":"Danon, Jeroen","last_name":"Danon","first_name":"Jeroen"},{"full_name":"Schrade, Constantin","last_name":"Schrade","first_name":"Constantin"},{"full_name":"Bakkers, Erik","last_name":"Bakkers","first_name":"Erik"},{"last_name":"Chrastina","first_name":"Daniel","full_name":"Chrastina, Daniel"},{"full_name":"Isella, Giovanni","last_name":"Isella","first_name":"Giovanni"},{"full_name":"Katsaros, Georgios","orcid":"0000-0001-8342-202X","first_name":"Georgios","id":"38DB5788-F248-11E8-B48F-1D18A9856A87","last_name":"Katsaros"}],"keyword":["Mesoscale and Nanoscale Physics"],"corr_author":"1","OA_place":"repository","language":[{"iso":"eng"}],"tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","short":"CC BY (4.0)"},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","article_processing_charge":"No","related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"13286"},{"id":"14793","status":"public","relation":"later_version"}]},"oa":1,"arxiv":1,"fulldoi":"https://doi.org/10.48550/arXiv.2306.07109","publication_status":"draft","title":"Radio frequency driven superconducting diode and parity conserving  Cooper pair transport in a two-dimensional germanium hole gas","project":[{"grant_number":"862046","_id":"237E5020-32DE-11EA-91FC-C7463DDC885E","name":"TOPOLOGICALLY PROTECTED AND SCALABLE QUANTUM BITS","call_identifier":"H2020"},{"call_identifier":"FWF","name":"Towards scalable hut wire quantum devices","grant_number":"P32235","_id":"237B3DA4-32DE-11EA-91FC-C7463DDC885E"},{"name":"Merging spin and superconducting qubits in planar Ge","_id":"bd8bd29e-d553-11ed-ba76-f0070d4b237a","grant_number":"P36507"},{"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"},{"_id":"eb9b30ac-77a9-11ec-83b8-871f581d53d2","name":"Protected states of quantum matter"}],"type":"preprint","ec_funded":1,"ddc":["530"],"status":"public"}]