[{"acknowledged_ssus":[{"_id":"NanoFab"}],"oa_version":"Preprint","project":[{"grant_number":"F07105","name":"Integrating superconducting quantum circuits","_id":"26927A52-B435-11E9-9278-68D0E5697425","call_identifier":"FWF"},{"name":"A Fiber Optic Transceiver for Superconducting Qubits","grant_number":"758053","_id":"26336814-B435-11E9-9278-68D0E5697425","call_identifier":"H2020"},{"_id":"eb9b30ac-77a9-11ec-83b8-871f581d53d2","name":"Protected states of quantum matter"},{"call_identifier":"H2020","_id":"258047B6-B435-11E9-9278-68D0E5697425","grant_number":"707438","name":"Microwave-to-Optical Quantum Link: Quantum Teleportation and Quantum Illumination with cavity Optomechanics SUPEREOM"},{"grant_number":"101080139","name":"Open Superconducting Quantum Computers (OpenSuperQPlus)","_id":"bdb7cfc1-d553-11ed-ba76-d2eaab167738"}],"month":"10","article_number":"044054","publication":"Physical Review Applied","language":[{"iso":"eng"}],"publication_identifier":{"eissn":["2331-7019"]},"oa":1,"date_published":"2023-10-20T00:00:00Z","type":"journal_article","main_file_link":[{"url":"https://arxiv.org/abs/2206.14104","open_access":"1"}],"related_material":{"record":[{"id":"14520","relation":"research_data","status":"public"}]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","status":"public","publication_status":"published","department":[{"_id":"JoFi"}],"date_created":"2023-11-12T23:00:55Z","article_processing_charge":"No","title":"Compact vacuum-gap transmon qubits: Selective and sensitive probes for superconductor surface losses","intvolume":"        20","_id":"14517","scopus_import":"1","author":[{"id":"2DCF8DE6-F248-11E8-B48F-1D18A9856A87","first_name":"Martin","last_name":"Zemlicka","full_name":"Zemlicka, Martin"},{"id":"2C21D6E8-F248-11E8-B48F-1D18A9856A87","first_name":"Elena","last_name":"Redchenko","full_name":"Redchenko, Elena"},{"last_name":"Peruzzo","first_name":"Matilda","full_name":"Peruzzo, Matilda","orcid":"0000-0002-3415-4628","id":"3F920B30-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Hassani","first_name":"Farid","full_name":"Hassani, Farid","orcid":"0000-0001-6937-5773","id":"2AED110C-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Andrea","last_name":"Trioni","full_name":"Trioni, Andrea","id":"42F71B44-F248-11E8-B48F-1D18A9856A87"},{"id":"2D25E1F6-F248-11E8-B48F-1D18A9856A87","full_name":"Barzanjeh, Shabir","orcid":"0000-0003-0415-1423","last_name":"Barzanjeh","first_name":"Shabir"},{"orcid":"0000-0001-8112-028X","full_name":"Fink, Johannes M","first_name":"Johannes M","last_name":"Fink","id":"4B591CBA-F248-11E8-B48F-1D18A9856A87"}],"issue":"4","publisher":"American Physical Society","article_type":"original","quality_controlled":"1","ec_funded":1,"doi":"10.1103/PhysRevApplied.20.044054","arxiv":1,"day":"20","abstract":[{"lang":"eng","text":"State-of-the-art transmon qubits rely on large capacitors, which systematically improve their coherence due to reduced surface-loss participation. However, this approach increases both the footprint and the parasitic cross-coupling and is ultimately limited by radiation losses—a potential roadblock for scaling up quantum processors to millions of qubits. In this work we present transmon qubits with sizes as low as 36 × 39 µm2 with  100-nm-wide vacuum-gap capacitors that are micromachined from commercial silicon-on-insulator wafers and shadow evaporated with aluminum. We achieve a vacuum participation ratio up to 99.6% in an in-plane design that is compatible with standard coplanar circuits. Qubit relaxationtime measurements for small gaps with high zero-point electric field variance of up to 22 V/m reveal a double exponential decay indicating comparably strong qubit interaction with long-lived two-level systems. The exceptionally high selectivity of up to 20 dB to the superconductor-vacuum interface allows us to precisely back out the sub-single-photon dielectric loss tangent of aluminum oxide previously exposed to ambient conditions. In terms of future scaling potential, we achieve a ratio of qubit quality factor to a footprint area equal to 20 µm−2, which is comparable with the highest T1 devices relying on larger geometries, a value that could improve substantially for lower surface-loss superconductors. "}],"date_updated":"2024-08-07T07:11:55Z","citation":{"apa":"Zemlicka, M., Redchenko, E., Peruzzo, M., Hassani, F., Trioni, A., Barzanjeh, S., &#38; Fink, J. M. (2023). Compact vacuum-gap transmon qubits: Selective and sensitive probes for superconductor surface losses. <i>Physical Review Applied</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevApplied.20.044054\">https://doi.org/10.1103/PhysRevApplied.20.044054</a>","ama":"Zemlicka M, Redchenko E, Peruzzo M, et al. Compact vacuum-gap transmon qubits: Selective and sensitive probes for superconductor surface losses. <i>Physical Review Applied</i>. 2023;20(4). doi:<a href=\"https://doi.org/10.1103/PhysRevApplied.20.044054\">10.1103/PhysRevApplied.20.044054</a>","chicago":"Zemlicka, Martin, Elena Redchenko, Matilda Peruzzo, Farid Hassani, Andrea Trioni, Shabir Barzanjeh, and Johannes M Fink. “Compact Vacuum-Gap Transmon Qubits: Selective and Sensitive Probes for Superconductor Surface Losses.” <i>Physical Review Applied</i>. American Physical Society, 2023. <a href=\"https://doi.org/10.1103/PhysRevApplied.20.044054\">https://doi.org/10.1103/PhysRevApplied.20.044054</a>.","ieee":"M. Zemlicka <i>et al.</i>, “Compact vacuum-gap transmon qubits: Selective and sensitive probes for superconductor surface losses,” <i>Physical Review Applied</i>, vol. 20, no. 4. American Physical Society, 2023.","mla":"Zemlicka, Martin, et al. “Compact Vacuum-Gap Transmon Qubits: Selective and Sensitive Probes for Superconductor Surface Losses.” <i>Physical Review Applied</i>, vol. 20, no. 4, 044054, American Physical Society, 2023, doi:<a href=\"https://doi.org/10.1103/PhysRevApplied.20.044054\">10.1103/PhysRevApplied.20.044054</a>.","short":"M. Zemlicka, E. Redchenko, M. Peruzzo, F. Hassani, A. Trioni, S. Barzanjeh, J.M. Fink, Physical Review Applied 20 (2023).","ista":"Zemlicka M, Redchenko E, Peruzzo M, Hassani F, Trioni A, Barzanjeh S, Fink JM. 2023. Compact vacuum-gap transmon qubits: Selective and sensitive probes for superconductor surface losses. Physical Review Applied. 20(4), 044054."},"year":"2023","external_id":{"arxiv":["2206.14104"]},"acknowledgement":"This work was supported by the Austrian Science Fund (FWF) through BeyondC (F7105), the European Research Council under Grant Agreement No. 758053 (ERC StG QUNNECT) and a NOMIS foundation research grant. M.Z. was the recipient of a SAIA scholarship, E.R. of\r\na DOC fellowship of the Austrian Academy of Sciences, and M.P. of a Pöttinger scholarship at IST Austria. S.B. acknowledges support from Marie Skłodowska Curie Program No. 707438 (MSC-IF SUPEREOM). J.M.F. acknowledges support from the Horizon Europe Program HORIZON-CL4-2022-QUANTUM-01-SGA via Project No. 101113946 OpenSuperQPlus100 and the ISTA Nanofabrication Facility.","volume":20},{"date_published":"2023-05-24T00:00:00Z","type":"journal_article","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"oa":1,"publication_identifier":{"eissn":["2041-1723"]},"related_material":{"record":[{"relation":"research_data","id":"13124","status":"public"}]},"status":"public","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","file":[{"date_created":"2023-06-06T07:31:20Z","file_size":1654389,"checksum":"a857df40f0882859c48a1ff1e2001ec2","date_updated":"2023-06-06T07:31:20Z","file_name":"2023_NaturePhysics_Redchenko.pdf","content_type":"application/pdf","success":1,"access_level":"open_access","relation":"main_file","file_id":"13123","creator":"dernst"}],"publication":"Nature Communications","has_accepted_license":"1","month":"05","article_number":"2998","oa_version":"Published Version","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"project":[{"grant_number":"F07105","name":"Integrating superconducting quantum circuits","_id":"26927A52-B435-11E9-9278-68D0E5697425","call_identifier":"FWF"},{"_id":"26336814-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","grant_number":"758053","name":"A Fiber Optic Transceiver for Superconducting Qubits"},{"name":"Controllable Collective States of Superconducting Qubit Ensembles","_id":"26B354CA-B435-11E9-9278-68D0E5697425"},{"_id":"eb9b30ac-77a9-11ec-83b8-871f581d53d2","name":"Protected states of quantum matter"}],"language":[{"iso":"eng"}],"isi":1,"external_id":{"arxiv":["2205.03293"],"isi":["001001099700002"]},"date_updated":"2024-08-07T07:11:50Z","citation":{"chicago":"Redchenko, Elena, Alexander V. Poshakinskiy, Riya Sett, Martin Zemlicka, Alexander N. Poddubny, and Johannes M Fink. “Tunable Directional Photon Scattering from a Pair of Superconducting Qubits.” <i>Nature Communications</i>. Springer Nature, 2023. <a href=\"https://doi.org/10.1038/s41467-023-38761-6\">https://doi.org/10.1038/s41467-023-38761-6</a>.","ieee":"E. Redchenko, A. V. Poshakinskiy, R. Sett, M. Zemlicka, A. N. Poddubny, and J. M. Fink, “Tunable directional photon scattering from a pair of superconducting qubits,” <i>Nature Communications</i>, vol. 14. Springer Nature, 2023.","apa":"Redchenko, E., Poshakinskiy, A. V., Sett, R., Zemlicka, M., Poddubny, A. N., &#38; Fink, J. M. (2023). Tunable directional photon scattering from a pair of superconducting qubits. <i>Nature Communications</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41467-023-38761-6\">https://doi.org/10.1038/s41467-023-38761-6</a>","ama":"Redchenko E, Poshakinskiy AV, Sett R, Zemlicka M, Poddubny AN, Fink JM. Tunable directional photon scattering from a pair of superconducting qubits. <i>Nature Communications</i>. 2023;14. doi:<a href=\"https://doi.org/10.1038/s41467-023-38761-6\">10.1038/s41467-023-38761-6</a>","ista":"Redchenko E, Poshakinskiy AV, Sett R, Zemlicka M, Poddubny AN, Fink JM. 2023. Tunable directional photon scattering from a pair of superconducting qubits. Nature Communications. 14, 2998.","mla":"Redchenko, Elena, et al. “Tunable Directional Photon Scattering from a Pair of Superconducting Qubits.” <i>Nature Communications</i>, vol. 14, 2998, Springer Nature, 2023, doi:<a href=\"https://doi.org/10.1038/s41467-023-38761-6\">10.1038/s41467-023-38761-6</a>.","short":"E. Redchenko, A.V. Poshakinskiy, R. Sett, M. Zemlicka, A.N. Poddubny, J.M. Fink, Nature Communications 14 (2023)."},"year":"2023","abstract":[{"text":"The ability to control the direction of scattered light is crucial to provide flexibility and scalability for a wide range of on-chip applications, such as integrated photonics, quantum information processing, and nonlinear optics. Tunable directionality can be achieved by applying external magnetic fields that modify optical selection rules, by using nonlinear effects, or interactions with vibrations. However, these approaches are less suitable to control microwave photon propagation inside integrated superconducting quantum devices. Here, we demonstrate on-demand tunable directional scattering based on two periodically modulated transmon qubits coupled to a transmission line at a fixed distance. By changing the relative phase between the modulation tones, we realize unidirectional forward or backward photon scattering. Such an in-situ switchable mirror represents a versatile tool for intra- and inter-chip microwave photonic processors. In the future, a lattice of qubits can be used to realize topological circuits that exhibit strong nonreciprocity or chirality.","lang":"eng"}],"doi":"10.1038/s41467-023-38761-6","arxiv":1,"day":"24","ddc":["530"],"volume":14,"acknowledgement":"The authors thank W.D. Oliver for discussions, L. Drmic and P. Zielinski for software development, and the MIBA workshop and the IST nanofabrication facility for technical support. This work was supported by the Austrian Science Fund (FWF) through BeyondC (F7105) and IST Austria. E.R. is the recipient of a DOC fellowship of the Austrian Academy of Sciences at IST Austria. J.M.F. and M.Z. acknowledge support from the European Research Council under grant agreement No 758053 (ERC StG QUNNECT) and a NOMIS foundation research grant. The work of A.N.P. and A.V.P. has been supported by the Russian Science Foundation under the grant No 20-12-00194.","author":[{"id":"2C21D6E8-F248-11E8-B48F-1D18A9856A87","last_name":"Redchenko","first_name":"Elena","full_name":"Redchenko, Elena"},{"last_name":"Poshakinskiy","first_name":"Alexander V.","full_name":"Poshakinskiy, Alexander V."},{"id":"2E6D040E-F248-11E8-B48F-1D18A9856A87","full_name":"Sett, Riya","last_name":"Sett","first_name":"Riya"},{"id":"2DCF8DE6-F248-11E8-B48F-1D18A9856A87","full_name":"Zemlicka, Martin","first_name":"Martin","last_name":"Zemlicka"},{"last_name":"Poddubny","first_name":"Alexander N.","full_name":"Poddubny, Alexander N."},{"orcid":"0000-0001-8112-028X","full_name":"Fink, Johannes M","first_name":"Johannes M","last_name":"Fink","id":"4B591CBA-F248-11E8-B48F-1D18A9856A87"}],"_id":"13117","scopus_import":"1","title":"Tunable directional photon scattering from a pair of superconducting qubits","intvolume":"        14","publication_status":"published","date_created":"2023-06-04T22:01:02Z","department":[{"_id":"JoFi"}],"article_processing_charge":"No","file_date_updated":"2023-06-06T07:31:20Z","quality_controlled":"1","ec_funded":1,"article_type":"original","publisher":"Springer Nature"},{"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.).","volume":19,"ddc":["530"],"year":"2023","citation":{"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>.","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.","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>","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>.","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."},"date_updated":"2024-01-29T11:27:49Z","external_id":{"isi":["001054563800006"]},"isi":1,"day":"01","doi":"10.1038/s41567-023-02161-w","abstract":[{"lang":"eng","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."}],"quality_controlled":"1","ec_funded":1,"page":"1630-1635","file_date_updated":"2024-01-29T11:25:38Z","publisher":"Springer Nature","article_type":"original","scopus_import":"1","_id":"14032","author":[{"first_name":"Soham","last_name":"Mukhopadhyay","full_name":"Mukhopadhyay, Soham","id":"FDE60288-A89D-11E9-947F-1AF6E5697425"},{"full_name":"Senior, Jorden L","orcid":"0000-0002-0672-9295","last_name":"Senior","first_name":"Jorden L","id":"5479D234-2D30-11EA-89CC-40953DDC885E"},{"full_name":"Saez Mollejo, Jaime","first_name":"Jaime","last_name":"Saez Mollejo","id":"e0390f72-f6e0-11ea-865d-862393336714"},{"first_name":"Denise","last_name":"Puglia","orcid":"0000-0003-1144-2763","full_name":"Puglia, Denise","id":"4D495994-AE37-11E9-AC72-31CAE5697425"},{"id":"2DCF8DE6-F248-11E8-B48F-1D18A9856A87","full_name":"Zemlicka, Martin","last_name":"Zemlicka","first_name":"Martin"},{"id":"4B591CBA-F248-11E8-B48F-1D18A9856A87","full_name":"Fink, Johannes M","orcid":"0000-0001-8112-028X","last_name":"Fink","first_name":"Johannes M"},{"last_name":"Higginbotham","first_name":"Andrew P","full_name":"Higginbotham, Andrew P","orcid":"0000-0003-2607-2363","id":"4AD6785A-F248-11E8-B48F-1D18A9856A87"}],"department":[{"_id":"GradSch"},{"_id":"AnHi"},{"_id":"JoFi"}],"date_created":"2023-08-11T07:41:17Z","article_processing_charge":"Yes (in subscription journal)","publication_status":"published","intvolume":"        19","title":"Superconductivity from a melted insulator in Josephson junction arrays","file":[{"date_created":"2024-01-29T11:25:38Z","checksum":"1fc86d71bfbf836e221c1e925343adc5","file_size":1977706,"date_updated":"2024-01-29T11:25:38Z","file_name":"2023_NaturePhysics_Mukhopadhyay.pdf","content_type":"application/pdf","success":1,"access_level":"open_access","relation":"main_file","file_id":"14899","creator":"dernst"}],"status":"public","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"type":"journal_article","date_published":"2023-11-01T00:00:00Z","publication_identifier":{"issn":["1745-2473"],"eissn":["1745-2481"]},"oa":1,"keyword":["General Physics and Astronomy"],"language":[{"iso":"eng"}],"has_accepted_license":"1","publication":"Nature Physics","project":[{"_id":"0aa3608a-070f-11eb-9043-e9cd8a2bd931","grant_number":"P33692","name":"Cavity electromechanics across a quantum phase transition"},{"name":"ISTplus - Postdoctoral Fellowships","grant_number":"754411","_id":"260C2330-B435-11E9-9278-68D0E5697425","call_identifier":"H2020"},{"name":"Protected states of quantum matter","_id":"eb9b30ac-77a9-11ec-83b8-871f581d53d2"},{"name":"Protected states of quantum matter","_id":"bd5b4ec5-d553-11ed-ba76-a6eedb083344"}],"oa_version":"Published Version","acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"NanoFab"}],"month":"11"}]