--- APC_amount: 7068 EUR DOAJ_listed: '1' OA_place: publisher OA_type: gold _id: '19401' abstract: - lang: eng text: High kinetic inductance superconductors are gaining increasing interest for the realisation of qubits, amplifiers and detectors. Moreover, thanks to their high impedance, quantum buses made of such materials enable large zero-point fluctuations of the voltage, boosting the coupling rates to spin and charge qubits. However, fully exploiting the potential of disordered or granular superconductors is challenging, as their inductance and, therefore, impedance at high values are difficult to control. Here, we report a reproducible fabrication of granular aluminium resonators by developing a wireless ohmmeter, which allows in situ measurements during film deposition and, therefore, control of the kinetic inductance of granular aluminium films. Reproducible fabrication of circuits with impedances (inductances) exceeding 13 kΩ (1 nH per square) is now possible. By integrating a 7.9 kΩ resonator with a germanium double quantum dot, we demonstrate strong charge-photon coupling with a rate of gc/2π = 566 ± 2 MHz. This broadly applicable method opens the path for novel qubits and high-fidelity, long-distance two-qubit gates. acknowledged_ssus: - _id: M-Shop - _id: NanoFab acknowledgement: 'We acknowledge Franco De Palma, Mahya Khorramshahi, Fabian Oppliger, Thomas Reisinger, Pasquale Scarlino and Xiao Xue for helpful discussions. We thank Simon Robson for proofreading 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. This research and related results were made possible with the support of the NOMIS Foundation and the HORIZON-RIA 101069515 project. This research was funded in whole or in part by the Austrian Science Fund (FWF) https://doi.org/10.55776/P32235, https://doi.org/10.55776/I5060 and https://doi.org/10.55776/P36507. For Open Access purposes, the author has applied a CC BY public copyright license to any author accepted manuscript version arising from this submission. M.J. acknowledges funding from FellowQUTE 2024-01. K.R. acknowledges funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No. 101034413. I.M.P. acknowledges funding from the Deutsche Forschungsgemeinschaft (DFG - German Research Foundation) under project number 450396347 (GeHoldeQED). ICN2 acknowledges funding from Generalitat de Catalunya 2021SGR00457. We acknowledge support from CSIC Interdisciplinary Thematic Platform (PTI+) on Quantum Technologies (PTI-QTEP+). This research work has been funded by the European Commission - NextGenerationEU (Regulation EU 2020/2094), through CSIC’s Quantum Technologies Platform (QTEP). ICN2 is supported by the Severo Ochoa programme from Spanish MCIN/AEI (Grant No.: CEX2021-001214-S) and is funded by the CERCA Programme/Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Autònoma de Barcelona Materials Science PhD programme. AGM has received funding from Grant RYC2021-033479-I funded by MCIN/AEI/10.13039/501100011033 and by European Union NextGenerationEU/PRTR. M.B. acknowledges support from SUR Generalitat de Catalunya and the EU Social Fund; project ref. 2020 FI 00103. The authors acknowledge the use of instrumentation and the technical advice provided by the Joint Electron Microscopy Centre at ALBA (JEMCA). ICN2 acknowledges funding from Grant IU16-014206 (METCAM-FIB) funded by the European Union through the European Regional Development Fund (ERDF), with the support of the Ministry of Research and Universities, Generalitat de Catalunya. ICN2 is a founding member of e-DREAM60.' article_number: '2103' article_processing_charge: Yes article_type: original arxiv: 1 author: - first_name: Marian full_name: Janik, Marian id: 396A1950-F248-11E8-B48F-1D18A9856A87 last_name: Janik orcid: 0009-0003-9037-8831 - first_name: Kevin Etienne Robert full_name: Roux, Kevin Etienne Robert id: 53f93ea2-803f-11ed-ab7e-b283135794ef last_name: Roux - first_name: Carla N full_name: Borja Espinosa, Carla N id: 18777c01-896a-11ed-bdf8-e4851dc07d16 last_name: Borja Espinosa - first_name: Oliver full_name: Sagi, Oliver id: 71616374-A8E9-11E9-A7CA-09ECE5697425 last_name: Sagi - first_name: Abdulhamid full_name: Baghdadi, Abdulhamid id: 160D87FA-96B5-11E9-BF77-7626E6697425 last_name: Baghdadi - first_name: Thomas full_name: Adletzberger, Thomas id: 38756BB2-F248-11E8-B48F-1D18A9856A87 last_name: Adletzberger - first_name: Stefano full_name: Calcaterra, Stefano last_name: Calcaterra - first_name: Marc full_name: Botifoll, Marc last_name: Botifoll - first_name: Alba full_name: Garzón Manjón, Alba last_name: Garzón Manjón - first_name: Jordi full_name: Arbiol, Jordi last_name: Arbiol - first_name: Daniel full_name: Chrastina, Daniel last_name: Chrastina - first_name: Giovanni full_name: Isella, Giovanni last_name: Isella - first_name: Ioan M. full_name: Pop, Ioan M. last_name: Pop - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Janik M, Roux KER, Borja Espinosa CN, et al. Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors. Nature Communications. 2025;16. doi:10.1038/s41467-025-57252-4 apa: Janik, M., Roux, K. E. R., Borja Espinosa, C. N., Sagi, O., Baghdadi, A., Adletzberger, T., … Katsaros, G. (2025). Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors. Nature Communications. Springer Nature. https://doi.org/10.1038/s41467-025-57252-4 chicago: Janik, Marian, Kevin Etienne Robert Roux, Carla N Borja Espinosa, Oliver Sagi, Abdulhamid Baghdadi, Thomas Adletzberger, Stefano Calcaterra, et al. “Strong Charge-Photon Coupling in Planar Germanium Enabled by Granular Aluminium Superinductors.” Nature Communications. Springer Nature, 2025. https://doi.org/10.1038/s41467-025-57252-4. ieee: M. Janik et al., “Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors,” Nature Communications, vol. 16. Springer Nature, 2025. ista: Janik M, Roux KER, Borja Espinosa CN, Sagi O, Baghdadi A, Adletzberger T, Calcaterra S, Botifoll M, Garzón Manjón A, Arbiol J, Chrastina D, Isella G, Pop IM, Katsaros G. 2025. Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors. Nature Communications. 16, 2103. mla: Janik, Marian, et al. “Strong Charge-Photon Coupling in Planar Germanium Enabled by Granular Aluminium Superinductors.” Nature Communications, vol. 16, 2103, Springer Nature, 2025, doi:10.1038/s41467-025-57252-4. short: M. Janik, K.E.R. Roux, C.N. Borja Espinosa, O. Sagi, A. Baghdadi, T. Adletzberger, S. Calcaterra, M. Botifoll, A. Garzón Manjón, J. Arbiol, D. Chrastina, G. Isella, I.M. Pop, G. Katsaros, Nature Communications 16 (2025). corr_author: '1' date_created: 2025-03-16T23:01:23Z date_published: 2025-03-01T00:00:00Z date_updated: 2026-05-20T06:34:51Z day: '01' ddc: - '530' department: - _id: GeKa - _id: JoFi - _id: M-Shop doi: 10.1038/s41467-025-57252-4 ec_funded: 1 external_id: arxiv: - '2407.03079' isi: - '001434774800001' pmid: - '40025007' file: - access_level: open_access checksum: a9383dd978ca2c50b7dded6c0bb2cd49 content_type: application/pdf creator: dernst date_created: 2025-03-17T10:53:32Z date_updated: 2025-03-17T10:53:32Z file_id: '19415' file_name: 2025_NatureComm_Janik.pdf file_size: 6364878 relation: main_file success: 1 file_date_updated: 2025-03-17T10:53:32Z has_accepted_license: '1' intvolume: ' 16' isi: 1 language: - iso: eng license: https://creativecommons.org/licenses/by/4.0/ month: '03' oa: 1 oa_version: Published Version pmid: 1 project: - _id: 34c0acea-11ca-11ed-8bc3-8775e10fd452 grant_number: '101069515' name: Integrated Germanium Quantum Technology - _id: 237B3DA4-32DE-11EA-91FC-C7463DDC885E call_identifier: FWF grant_number: P32235 name: Towards scalable hut wire quantum devices - _id: c0977eea-5a5b-11eb-8a69-a862db0cf4d1 grant_number: I05060 name: High impedance circuit quantum electrodynamics with hole spins - _id: bd8bd29e-d553-11ed-ba76-f0070d4b237a grant_number: P36507 name: Merging spin and superconducting qubits in planar Ge - _id: fc2ed2f7-9c52-11eb-aca3-c01059dda49c call_identifier: H2020 grant_number: '101034413' name: 'IST-BRIDGE: International postdoctoral program' - _id: 3AC91DDA-15DF-11EA-824D-93A3E7B544D1 call_identifier: FWF name: FWF Open Access Fund publication: Nature Communications publication_identifier: eissn: - 2041-1723 publication_status: published publisher: Springer Nature quality_controlled: '1' related_material: record: - id: '18144' relation: earlier_version status: public - id: '18886' relation: research_data status: public scopus_import: '1' status: public title: Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 16 year: '2025' ... --- OA_place: repository OA_type: gold _id: '18886' abstract: - lang: eng text: Research Data for publication 'Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors' acknowledged_ssus: - _id: M-Shop - _id: NanoFab acknowledgement: 'We acknowledge Franco De Palma, Mahya Khorramshahi, Fabian Oppliger, Thomas Reisinger, Pasquale Scarlino and Xiao Xue for helpful discussions. We thank Simon Robson for proofreading 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. This research and related results were made possible with the support of the NOMIS Foundation and the HORIZON-RIA 101069515 project. This research was funded in whole or in part by the Austrian Science Fund (FWF) DOI:10.55776/P32235, DOI:10.55776/I5060 and DOI:10.55776/P36507. For Open Access purposes, the author has applied a CC BY public copyright license to any author accepted manuscript version arising from this submission. M.J. acknowledges funding from FellowQUTE 2024-01. I.M.P. acknowledges funding from the Deutsche Forschungsgemeinschaft (DFG – German Research Foundation) under project number 450396347 (GeHoldeQED). ICN2 acknowledges funding from Generalitat de Catalunya 2021SGR00457. We acknowledge support from CSIC Interdisciplinary Thematic Platform (PTI+) on Quantum Technologies (PTI-QTEP+). This research work has been funded by the European Commission – NextGenerationEU (Regulation EU 2020/2094), through CSIC''s Quantum Technologies Platform (QTEP). ICN2 is supported by the Severo Ochoa program from Spanish MCIN/AEI (Grant No.: CEX2021-001214-S) and is funded by the CERCA Programme/Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Autònoma de Barcelona Materials Science PhD program. AGM has received funding from Grant RYC2021-033479-I funded by MCIN/AEI/10.13039/501100011033 and by European Union NextGenerationEU/PRTR. M.B. acknowledges support from SUR Generalitat de Catalunya and the EU Social Fund; project ref. 2020 FI 00103. The authors acknowledge the use of instrumentation and the technical advice provided by the Joint Electron Microscopy Center at ALBA (JEMCA). ICN2 acknowledges funding from Grant IU16-014206 (METCAM-FIB) funded by the European Union through the European Regional Development Fund (ERDF), with the support of the Ministry of Research and Universities, Generalitat de Catalunya. ICN2 is a founding member of e-DREAM.' article_processing_charge: No author: - first_name: Marian full_name: Janik, Marian id: 396A1950-F248-11E8-B48F-1D18A9856A87 last_name: Janik orcid: 0009-0003-9037-8831 citation: ama: Janik M. Research data for publication “Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors.” 2025. doi:10.15479/AT:ISTA:18886 apa: Janik, M. (2025). Research data for publication “Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors.” Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:18886 chicago: Janik, Marian. “Research Data for Publication ‘Strong Charge-Photon Coupling in Planar Germanium Enabled by Granular Aluminium Superinductors.’” Institute of Science and Technology Austria, 2025. https://doi.org/10.15479/AT:ISTA:18886. ieee: M. Janik, “Research data for publication ‘Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors.’” Institute of Science and Technology Austria, 2025. ista: Janik M. 2025. Research data for publication ‘Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors’, Institute of Science and Technology Austria, 10.15479/AT:ISTA:18886. mla: Janik, Marian. Research Data for Publication “Strong Charge-Photon Coupling in Planar Germanium Enabled by Granular Aluminium Superinductors.” Institute of Science and Technology Austria, 2025, doi:10.15479/AT:ISTA:18886. short: M. Janik, (2025). contributor: - contributor_type: researcher first_name: Kevin Etienne Robert id: 53f93ea2-803f-11ed-ab7e-b283135794ef last_name: Roux - contributor_type: researcher first_name: Carla N id: 18777c01-896a-11ed-bdf8-e4851dc07d16 last_name: Borja Espinosa - contributor_type: researcher first_name: Oliver id: 71616374-A8E9-11E9-A7CA-09ECE5697425 last_name: Sagi - contributor_type: researcher first_name: Abdulhamid id: 160D87FA-96B5-11E9-BF77-7626E6697425 last_name: Baghdadi - contributor_type: researcher first_name: Thomas id: 38756BB2-F248-11E8-B48F-1D18A9856A87 last_name: Adletzberger - contributor_type: researcher first_name: Stefano last_name: Calcaterra - contributor_type: researcher first_name: Marc last_name: Botifoll - contributor_type: researcher first_name: Alba Garzón last_name: Manjón - contributor_type: researcher first_name: Jordi last_name: Arbiol - contributor_type: researcher first_name: Daniel last_name: Chrastina - contributor_type: researcher first_name: Giovanni last_name: Isella - contributor_type: researcher first_name: Ioan M. last_name: Pop - contributor_type: researcher first_name: Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X corr_author: '1' date_created: 2025-01-27T09:48:44Z date_published: 2025-01-27T00:00:00Z date_updated: 2026-05-20T06:34:50Z day: '27' ddc: - '530' department: - _id: GeKa - _id: GradSch doi: 10.15479/AT:ISTA:18886 file: - access_level: open_access checksum: 977dffed4bec3c7d6315aa1cbd19e8a7 content_type: text/plain creator: arashid date_created: 2025-01-27T11:27:30Z date_updated: 2025-01-27T11:27:30Z file_id: '18893' file_name: readme.txt file_size: 1017 relation: main_file success: 1 - access_level: open_access checksum: 7ab5e3e65ddf59bbf3622ace8a0cda1c content_type: application/zip creator: arashid date_created: 2025-01-27T11:27:35Z date_updated: 2025-01-27T11:27:35Z file_id: '18894' file_name: research_data.zip file_size: 33815056 relation: main_file success: 1 file_date_updated: 2025-01-27T11:27:35Z has_accepted_license: '1' month: '01' oa: 1 oa_version: Published Version project: - _id: 34c0acea-11ca-11ed-8bc3-8775e10fd452 grant_number: '101069515' name: Integrated Germanium Quantum Technology - _id: 237B3DA4-32DE-11EA-91FC-C7463DDC885E call_identifier: FWF grant_number: P32235 name: Towards scalable hut wire quantum devices - _id: bd8bd29e-d553-11ed-ba76-f0070d4b237a grant_number: P36507 name: Merging spin and superconducting qubits in planar Ge - _id: c0977eea-5a5b-11eb-8a69-a862db0cf4d1 grant_number: I05060 name: High impedance circuit quantum electrodynamics with hole spins publisher: Institute of Science and Technology Austria related_material: record: - id: '18144' relation: used_in_publication status: public - id: '19401' relation: used_in_publication status: public status: public title: Research data for publication 'Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors' tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: research_data user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2025' ... --- DOAJ_listed: '1' OA_place: publisher OA_type: gold _id: '18602' abstract: - lang: eng text: Semiconductor quantum dots (QDs) in planar germanium (Ge) heterostructures have emerged as front-runners for future hole-based quantum processors. Here, we present strong coupling between a hole charge qubit, defined in a double quantum dot (DQD) in planar Ge, and microwave photons in a high-impedance (Zr = 1.3 kΩ) resonator based on an array of superconducting quantum interference devices (SQUIDs). Our investigation reveals vacuum-Rabi splittings with coupling strengths up to g0/2π = 260 MHz, and a cooperativity of C ~ 100, dependent on DQD tuning. Furthermore, utilizing the frequency tunability of our resonator, we explore the quenched energy splitting associated with strong Coulomb correlation effects in Ge QDs. The observed enhanced coherence of the strongly correlated excited state signals the presence of distinct symmetries within related spin functions, serving as a precursor to the strong coupling between photons and spin-charge hybrid qubits in planar Ge. This work paves the way towards coherent quantum connections between remote hole qubits in planar Ge, required to scale up hole-based quantum processors. acknowledgement: The authors thank Simone Frasca, Vincent Jouanny, Guillaume Beaulieu, Camille Roy, Dominic Dahinden, Davide Lombardo, Daniel Chrastina, and Siddhart Gautam for contributing to some cleanroom fabrication steps, the measurement setup, device simulations, data analysis, and for the useful discussions. P.S. acknowledges support from the Swiss National Science Foundation (SNSF) through the grants Ref. No. 200021 200418 and Ref. No. 206021_205335, and from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number 01042765 SEFRI MB22.00081. W.J. acknowledges support from the EPFL QSE Postdoctoral Fellowship Grant. S.B., D.L., and P.S. acknowledge support from the NCCR Spin Qubit in Silicon (NCCR-SPIN) Grant No. 51NF40-180604. M.J., G.K., G.I., and S.C. acknowledge support from the Horizon Europe Project IGNITE ID 101070193. G.K. acknowledges support from the FWF via the P32235 and I05060 projects. article_number: '10177' article_processing_charge: Yes article_type: original author: - first_name: Franco full_name: De Palma, Franco last_name: De Palma - first_name: Fabian full_name: Oppliger, Fabian last_name: Oppliger - first_name: Wonjin full_name: Jang, Wonjin last_name: Jang - first_name: Stefano full_name: Bosco, Stefano last_name: Bosco - first_name: Marian full_name: Janik, Marian id: 396A1950-F248-11E8-B48F-1D18A9856A87 last_name: Janik orcid: 0009-0003-9037-8831 - first_name: Stefano full_name: Calcaterra, Stefano last_name: Calcaterra - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X - first_name: Giovanni full_name: Isella, Giovanni last_name: Isella - first_name: Daniel full_name: Loss, Daniel last_name: Loss - first_name: Pasquale full_name: Scarlino, Pasquale last_name: Scarlino citation: ama: De Palma F, Oppliger F, Jang W, et al. Strong hole-photon coupling in planar Ge for probing charge degree and strongly correlated states. Nature Communications. 2024;15. doi:10.1038/s41467-024-54520-7 apa: De Palma, F., Oppliger, F., Jang, W., Bosco, S., Janik, M., Calcaterra, S., … Scarlino, P. (2024). Strong hole-photon coupling in planar Ge for probing charge degree and strongly correlated states. Nature Communications. Springer Nature. https://doi.org/10.1038/s41467-024-54520-7 chicago: De Palma, Franco, Fabian Oppliger, Wonjin Jang, Stefano Bosco, Marian Janik, Stefano Calcaterra, Georgios Katsaros, Giovanni Isella, Daniel Loss, and Pasquale Scarlino. “Strong Hole-Photon Coupling in Planar Ge for Probing Charge Degree and Strongly Correlated States.” Nature Communications. Springer Nature, 2024. https://doi.org/10.1038/s41467-024-54520-7. ieee: F. De Palma et al., “Strong hole-photon coupling in planar Ge for probing charge degree and strongly correlated states,” Nature Communications, vol. 15. Springer Nature, 2024. ista: De Palma F, Oppliger F, Jang W, Bosco S, Janik M, Calcaterra S, Katsaros G, Isella G, Loss D, Scarlino P. 2024. Strong hole-photon coupling in planar Ge for probing charge degree and strongly correlated states. Nature Communications. 15, 10177. mla: De Palma, Franco, et al. “Strong Hole-Photon Coupling in Planar Ge for Probing Charge Degree and Strongly Correlated States.” Nature Communications, vol. 15, 10177, Springer Nature, 2024, doi:10.1038/s41467-024-54520-7. short: F. De Palma, F. Oppliger, W. Jang, S. Bosco, M. Janik, S. Calcaterra, G. Katsaros, G. Isella, D. Loss, P. Scarlino, Nature Communications 15 (2024). date_created: 2024-12-01T23:01:53Z date_published: 2024-12-01T00:00:00Z date_updated: 2025-09-08T14:46:06Z day: '01' ddc: - '530' department: - _id: GeKa doi: 10.1038/s41467-024-54520-7 external_id: isi: - '001362684200001' pmid: - '39580488' file: - access_level: open_access checksum: ef9f99a84089c388904cc8aa8d89c55a content_type: application/pdf creator: dernst date_created: 2024-12-03T11:00:15Z date_updated: 2024-12-03T11:00:15Z file_id: '18611' file_name: 2024_NatureComm_dePalma.pdf file_size: 5288092 relation: main_file success: 1 file_date_updated: 2024-12-03T11:00:15Z has_accepted_license: '1' intvolume: ' 15' isi: 1 language: - iso: eng month: '12' oa: 1 oa_version: Published Version pmid: 1 project: - _id: 237B3DA4-32DE-11EA-91FC-C7463DDC885E call_identifier: FWF grant_number: P32235 name: Towards scalable hut wire quantum devices - _id: c0977eea-5a5b-11eb-8a69-a862db0cf4d1 grant_number: I05060 name: High impedance circuit quantum electrodynamics with hole spins publication: Nature Communications publication_identifier: eissn: - 2041-1723 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: Strong hole-photon coupling in planar Ge for probing charge degree and strongly correlated states tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 15 year: '2024' ... --- APC_amount: 6468 EUR DOAJ_listed: '1' OA_place: publisher OA_type: gold _id: '14793' 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. acknowledged_ssus: - _id: M-Shop - _id: NanoFab 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." article_number: '169' article_processing_charge: Yes article_type: original author: - first_name: Marco full_name: Valentini, Marco id: C0BB2FAC-D767-11E9-B658-BC13E6697425 last_name: Valentini - first_name: Oliver full_name: Sagi, Oliver id: 71616374-A8E9-11E9-A7CA-09ECE5697425 last_name: Sagi - first_name: Levon full_name: Baghumyan, Levon id: 7aa1f788-b527-11ee-aa9e-e6111a79e0c7 last_name: Baghumyan - first_name: Thijs full_name: de Gijsel, Thijs id: a0ece13c-b527-11ee-929d-bad130106eee last_name: de Gijsel - first_name: Jason full_name: Jung, Jason id: 4C9ACE7A-F248-11E8-B48F-1D18A9856A87 last_name: Jung - first_name: Stefano full_name: Calcaterra, Stefano last_name: Calcaterra - first_name: Andrea full_name: Ballabio, Andrea last_name: Ballabio - first_name: Juan L full_name: Aguilera Servin, Juan L id: 2A67C376-F248-11E8-B48F-1D18A9856A87 last_name: Aguilera Servin orcid: 0000-0002-2862-8372 - first_name: Kushagra full_name: Aggarwal, Kushagra id: b22ab905-3539-11eb-84c3-fc159dcd79cb last_name: Aggarwal orcid: 0000-0001-9985-9293 - first_name: Marian full_name: Janik, Marian id: 396A1950-F248-11E8-B48F-1D18A9856A87 last_name: Janik orcid: 0009-0003-9037-8831 - first_name: Thomas full_name: Adletzberger, Thomas id: 38756BB2-F248-11E8-B48F-1D18A9856A87 last_name: Adletzberger - first_name: Rubén full_name: Seoane Souto, Rubén last_name: Seoane Souto - first_name: Martin full_name: Leijnse, Martin last_name: Leijnse - first_name: Jeroen full_name: Danon, Jeroen last_name: Danon - first_name: Constantin full_name: Schrade, Constantin last_name: Schrade - first_name: Erik full_name: Bakkers, Erik last_name: Bakkers - first_name: Daniel full_name: Chrastina, Daniel last_name: Chrastina - first_name: Giovanni full_name: Isella, Giovanni last_name: Isella - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Valentini M, Sagi O, Baghumyan L, et al. Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium. Nature Communications. 2024;15. doi:10.1038/s41467-023-44114-0 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. Nature Communications. Springer Nature. https://doi.org/10.1038/s41467-023-44114-0 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.” Nature Communications. Springer Nature, 2024. https://doi.org/10.1038/s41467-023-44114-0. ieee: M. Valentini et al., “Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium,” Nature Communications, vol. 15. Springer Nature, 2024. 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. mla: Valentini, Marco, et al. “Parity-Conserving Cooper-Pair Transport and Ideal Superconducting Diode in Planar Germanium.” Nature Communications, vol. 15, 169, Springer Nature, 2024, doi:10.1038/s41467-023-44114-0. 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). corr_author: '1' date_created: 2024-01-14T23:00:56Z date_published: 2024-01-02T00:00:00Z date_updated: 2025-10-15T06:31:47Z day: '02' ddc: - '530' department: - _id: GeKa doi: 10.1038/s41467-023-44114-0 ec_funded: 1 external_id: isi: - '001142794000839' pmid: - '38167818' file: - access_level: open_access checksum: ef79173b45eeaf984ffa61ef2f8a52ab content_type: application/pdf creator: dernst date_created: 2024-01-17T11:03:00Z date_updated: 2024-01-17T11:03:00Z file_id: '14825' file_name: 2024_NatureComm_Valentini.pdf file_size: 2336595 relation: main_file success: 1 file_date_updated: 2024-01-17T11:03:00Z has_accepted_license: '1' intvolume: ' 15' isi: 1 language: - iso: eng month: '01' oa: 1 oa_version: Published Version pmid: 1 project: - _id: 237E5020-32DE-11EA-91FC-C7463DDC885E call_identifier: H2020 grant_number: '862046' name: TOPOLOGICALLY PROTECTED AND SCALABLE QUANTUM BITS - _id: 34c0acea-11ca-11ed-8bc3-8775e10fd452 grant_number: '101069515' name: Integrated Germanium Quantum Technology - _id: bdc2ca30-d553-11ed-ba76-cf164a5bb811 grant_number: '101115315' name: Quantum bits with Kitaev Transmons - _id: 237B3DA4-32DE-11EA-91FC-C7463DDC885E call_identifier: FWF grant_number: P32235 name: Towards scalable hut wire quantum devices - _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' - _id: 3AC91DDA-15DF-11EA-824D-93A3E7B544D1 call_identifier: FWF name: FWF Open Access Fund publication: Nature Communications publication_identifier: eissn: - 2041-1723 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 15 year: '2024' ... --- APC_amount: 6828 EUR DOAJ_listed: '1' OA_place: publisher OA_type: gold _id: '17202' abstract: - lang: eng text: Gate-tunable transmons (gatemons) employing semiconductor Josephson junctions have recently emerged as building blocks for hybrid quantum circuits. In this study, we present a gatemon fabricated in planar Germanium. We induce superconductivity in a two-dimensional hole gas by evaporating aluminum atop a thin spacer, which separates the superconductor from the Ge quantum well. The Josephson junction is then integrated into an Xmon circuit and capacitively coupled to a transmission line resonator. We showcase the qubit tunability in a broad frequency range with resonator and two-tone spectroscopy. Time-domain characterizations reveal energy relaxation and coherence times up to 75 ns. Our results, combined with the recent advances in the spin qubit field, pave the way towards novel hybrid and protected qubits in a group IV, CMOS-compatible material. acknowledged_ssus: - _id: ScienComp - _id: M-Shop - _id: NanoFab acknowledgement: "We acknowledge Lucas Casparis, Jeroen Danon, Valla Fatemi, Morten Kjaergard and Javad Shabani for their valuable insights and comments. This research was supported by the Scientific Service Units of ISTA through resources provided by the MIBA Machine Shop\r\nand the Nanofabrication facility. This research and related results were made possible with the support of the NOMIS Foundation and the FWF Projects with DOI:10.55776/I5060 and DOI:10.55776/P36507. We also acknowledge the NextGenerationEU PRIN project\r\n2022A8CJP3 (GAMESQUAD) for partial financial support." article_number: '6400' article_processing_charge: Yes article_type: original arxiv: 1 author: - first_name: Oliver full_name: Sagi, Oliver id: 71616374-A8E9-11E9-A7CA-09ECE5697425 last_name: Sagi - first_name: Alessandro full_name: Crippa, Alessandro id: 1F2B21A2-F6E7-11E9-9B82-F7DBE5697425 last_name: Crippa orcid: 0000-0002-2968-611X - first_name: Marco full_name: Valentini, Marco id: C0BB2FAC-D767-11E9-B658-BC13E6697425 last_name: Valentini - first_name: Marian full_name: Janik, Marian id: 396A1950-F248-11E8-B48F-1D18A9856A87 last_name: Janik orcid: 0009-0003-9037-8831 - first_name: Levon full_name: Baghumyan, Levon id: 7aa1f788-b527-11ee-aa9e-e6111a79e0c7 last_name: Baghumyan - first_name: Giorgio full_name: Fabris, Giorgio id: 298cf6f3-1ff6-11ee-9fa6-d94cfa0b3352 last_name: Fabris - first_name: Lucky full_name: Kapoor, Lucky id: 84b9700b-15b2-11ec-abd3-831089e67615 last_name: Kapoor orcid: 0000-0001-8319-2148 - first_name: Farid full_name: Hassani, Farid id: 2AED110C-F248-11E8-B48F-1D18A9856A87 last_name: Hassani orcid: 0000-0001-6937-5773 - first_name: Johannes M full_name: Fink, Johannes M id: 4B591CBA-F248-11E8-B48F-1D18A9856A87 last_name: Fink orcid: 0000-0001-8112-028X - first_name: Stefano full_name: Calcaterra, Stefano last_name: Calcaterra - first_name: Daniel full_name: Chrastina, Daniel last_name: Chrastina - first_name: Giovanni full_name: Isella, Giovanni last_name: Isella - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Sagi O, Crippa A, Valentini M, et al. A gate tunable transmon qubit in planar Ge. Nature Communications. 2024;15. doi:10.1038/s41467-024-50763-6 apa: Sagi, O., Crippa, A., Valentini, M., Janik, M., Baghumyan, L., Fabris, G., … Katsaros, G. (2024). A gate tunable transmon qubit in planar Ge. Nature Communications. Springer Nature. https://doi.org/10.1038/s41467-024-50763-6 chicago: Sagi, Oliver, Alessandro Crippa, Marco Valentini, Marian Janik, Levon Baghumyan, Giorgio Fabris, Lucky Kapoor, et al. “A Gate Tunable Transmon Qubit in Planar Ge.” Nature Communications. Springer Nature, 2024. https://doi.org/10.1038/s41467-024-50763-6. ieee: O. Sagi et al., “A gate tunable transmon qubit in planar Ge,” Nature Communications, vol. 15. Springer Nature, 2024. ista: Sagi O, Crippa A, Valentini M, Janik M, Baghumyan L, Fabris G, Kapoor L, Hassani F, Fink JM, Calcaterra S, Chrastina D, Isella G, Katsaros G. 2024. A gate tunable transmon qubit in planar Ge. Nature Communications. 15, 6400. mla: Sagi, Oliver, et al. “A Gate Tunable Transmon Qubit in Planar Ge.” Nature Communications, vol. 15, 6400, Springer Nature, 2024, doi:10.1038/s41467-024-50763-6. short: O. Sagi, A. Crippa, M. Valentini, M. Janik, L. Baghumyan, G. Fabris, L. Kapoor, F. Hassani, J.M. Fink, S. Calcaterra, D. Chrastina, G. Isella, G. Katsaros, Nature Communications 15 (2024). corr_author: '1' date_created: 2024-07-04T11:40:45Z date_published: 2024-07-30T00:00:00Z date_updated: 2026-04-07T13:01:55Z day: '30' ddc: - '530' department: - _id: GeKa - _id: JoFi - _id: GradSch doi: 10.1038/s41467-024-50763-6 external_id: arxiv: - '2403.16774' isi: - '001281271000022' pmid: - '39080279' file: - access_level: open_access checksum: ddf5361dcb6c543e2cea818501c09910 content_type: application/pdf creator: dernst date_created: 2024-08-05T08:38:01Z date_updated: 2024-08-05T08:38:01Z file_id: '17388' file_name: 2024_NatureComm_Sagi.pdf file_size: 1928001 relation: main_file success: 1 file_date_updated: 2024-08-05T08:38:01Z has_accepted_license: '1' intvolume: ' 15' isi: 1 language: - iso: eng month: '07' oa: 1 oa_version: Published Version pmid: 1 project: - _id: bd8bd29e-d553-11ed-ba76-f0070d4b237a grant_number: P36507 name: Merging spin and superconducting qubits in planar Ge - _id: c0977eea-5a5b-11eb-8a69-a862db0cf4d1 grant_number: I05060 name: High impedance circuit quantum electrodynamics with hole spins - _id: 262116AA-B435-11E9-9278-68D0E5697425 name: Hybrid Semiconductor - Superconductor Quantum Devices - _id: 3AC91DDA-15DF-11EA-824D-93A3E7B544D1 call_identifier: FWF name: FWF Open Access Fund publication: Nature Communications publication_identifier: eissn: - 2041-1723 publication_status: published publisher: Springer Nature quality_controlled: '1' related_material: link: - relation: erratum url: https://doi.org/10.1038/s41467-024-53910-1 record: - id: '17196' relation: research_data status: public - id: '18076' relation: dissertation_contains status: public scopus_import: '1' status: public title: A gate tunable transmon qubit in planar Ge tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345 volume: 15 year: '2024' ... --- OA_place: publisher _id: '18129' abstract: - lang: eng text: "State-of-the-art quantum computers, with roughly a thousand qubits, face a crucial technological challenge of scaling up. Spins confined in quantum dots (QDs) are a promising candidate\r\nfor qubits due to their long coherence, tunability, control, and readout. However, their natural\r\ncoupling is the short-ranged (∼ 100 nm) exchange interaction, limited to nearest neighbours.\r\nLong-ranged (∼ 1 mm) qubit interactions mediated by a photon could be engineered through a\r\ncoherent spin-photon coupling. Achieving a strong coupling to a photon is inherently challenging in QDs due to the small dipole moment of the confined charge. However, the potential of\r\nhigh-impedance resonators to compensate for this has gained significant attention in the past\r\ndecade. Nevertheless, previous QD circuit quantum electrodynamics implementations have not\r\nexceeded the impedance of ∼ 3.8 kΩ, leaving opportunities for significant improvement. The\r\nlarge kinetic inductance of granular aluminium (grAl) could provide an order-of-magnitude\r\nenhancement. However, fully exploiting the potential of disordered or granular superconductors\r\nis challenging as their impedances close to the superconductor-to-insulator transition are\r\ndifficult to control reproducibly. We report on the realization of a wireless ohmmeter which\r\nallows in situ resistance measurements during film deposition and, therefore, indirect control\r\nof the kinetic inductance of grAl films. This allows us to reproducibly fabricate resonators\r\nwith characteristic impedance exceeding the resistance quantum, even reaching 22.3 kW, due\r\nto the large sheet kinetic inductance of up to 3 nH □−1\r\n. By integrating an 8 kW resonator\r\nwith a germanium double QD, we demonstrate a strong charge-photon coupling with the\r\nhighest rate reported, 566 MHz. The demonstrated method and grAl properties make these\r\nresonators suitable for boosting the spin-photon coupling strength, a crucial requirement for\r\nfast, high-fidelity, long-distance two-qubit gates.\r\n" acknowledged_ssus: - _id: M-Shop - _id: NanoFab alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Marian full_name: Janik, Marian id: 396A1950-F248-11E8-B48F-1D18A9856A87 last_name: Janik orcid: 0009-0003-9037-8831 citation: ama: Janik M. Strong charge-photon coupling in Germanium enabled by granular aluminium superinductors. 2024. doi:10.15479/at:ista:18129 apa: Janik, M. (2024). Strong charge-photon coupling in Germanium enabled by granular aluminium superinductors. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:18129 chicago: Janik, Marian. “Strong Charge-Photon Coupling in Germanium Enabled by Granular Aluminium Superinductors.” Institute of Science and Technology Austria, 2024. https://doi.org/10.15479/at:ista:18129. ieee: M. Janik, “Strong charge-photon coupling in Germanium enabled by granular aluminium superinductors,” Institute of Science and Technology Austria, 2024. ista: Janik M. 2024. Strong charge-photon coupling in Germanium enabled by granular aluminium superinductors. Institute of Science and Technology Austria. mla: Janik, Marian. Strong Charge-Photon Coupling in Germanium Enabled by Granular Aluminium Superinductors. Institute of Science and Technology Austria, 2024, doi:10.15479/at:ista:18129. short: M. Janik, Strong Charge-Photon Coupling in Germanium Enabled by Granular Aluminium Superinductors, Institute of Science and Technology Austria, 2024. corr_author: '1' date_created: 2024-09-23T17:25:43Z date_published: 2024-09-24T00:00:00Z date_updated: 2026-04-07T13:23:25Z day: '24' ddc: - '539' degree_awarded: PhD department: - _id: GradSch - _id: GeKa doi: 10.15479/at:ista:18129 file: - access_level: closed checksum: dc15958f6400b5bdaa28bf58fc7a4056 content_type: application/x-zip-compressed creator: mjanik date_created: 2024-09-23T17:15:09Z date_updated: 2025-05-23T22:30:09Z embargo_to: open_access file_id: '18130' file_name: janik_thesis.zip file_size: 156207943 relation: source_file - access_level: open_access checksum: 74737aee285dc1f491643327350efe9c content_type: application/pdf creator: mjanik date_created: 2024-09-23T17:15:30Z date_updated: 2025-05-23T22:30:09Z embargo: 2025-05-23 file_id: '18131' file_name: janik_thesis_pdfa.pdf file_size: 96195684 relation: main_file file_date_updated: 2025-05-23T22:30:09Z has_accepted_license: '1' language: - iso: eng month: '09' oa: 1 oa_version: Published Version page: '164' project: - _id: c0977eea-5a5b-11eb-8a69-a862db0cf4d1 grant_number: I05060 name: High impedance circuit quantum electrodynamics with hole spins - _id: bd8bd29e-d553-11ed-ba76-f0070d4b237a grant_number: P36507 name: Merging spin and superconducting qubits in planar Ge - _id: 237B3DA4-32DE-11EA-91FC-C7463DDC885E call_identifier: FWF grant_number: P32235 name: Towards scalable hut wire quantum devices - _id: 34c0acea-11ca-11ed-8bc3-8775e10fd452 grant_number: '101069515' name: Integrated Germanium Quantum Technology - _id: eb9b30ac-77a9-11ec-83b8-871f581d53d2 name: Protected states of quantum matter publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '18144' relation: part_of_dissertation status: public status: public supervisor: - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X title: Strong charge-photon coupling in Germanium enabled by granular aluminium superinductors tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: dissertation user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd year: '2024' ... --- OA_place: repository _id: '18144' abstract: - lang: eng text: "High kinetic inductance superconductors are gaining increasing interest for\r\nthe realisation of qubits, amplifiers and detectors. Moreover, thanks to their\r\nhigh impedance, quantum buses made of such materials enable large zero-point\r\nfluctuations of the voltage, boosting the coupling rates to spin and charge\r\nqubits. However, fully exploiting the potential of disordered or granular\r\nsuperconductors is challenging, as their inductance and, therefore, impedance\r\nat high values are difficult to control. Here we have integrated a granular\r\naluminium resonator, having a characteristic impedance exceeding the resistance\r\nquantum, with a germanium double quantum dot and demonstrate strong\r\ncharge-photon coupling with a rate of $g_\\text{c}/2\\pi= (566 \\pm 2)$ MHz. This\r\nwas achieved due to the realisation of a wireless ohmmeter, which allows\r\n\\emph{in situ} measurements during film deposition and, therefore, control of\r\nthe kinetic inductance of granular aluminium films. Reproducible fabrication of\r\ncircuits with impedances (inductances) exceeding 13 k$\\Omega$ (1 nH per square)\r\nis now possible. This broadly applicable method opens the path for novel qubits\r\nand high-fidelity, long-distance two-qubit gates." acknowledged_ssus: - _id: M-Shop - _id: NanoFab acknowledgement: "We acknowledge Franco De Palma, Mahya Khorramshahi, Fabian Oppliger, Thomas Reisinger, Pasquale Scarlino and Xiao Xue 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, the FWF Projects with DOI:10.55776/P32235, DOI:10.55776/I5060 and DOI:10.55776/P36507. IMP acknowledges funding from the Deutsche Forschungsgemeinschaft (DFG – German Research Foundation) under project number 450396347 (GeHoldeQED). ICN2 acknowledges funding from Generalitat de Catalunya 2021SGR00457. We acknowledge support from CSIC Interdisciplinary Thematic Platform (PTI+) on Quantum Technologies (PTI-QTEP+). This research work has been funded by the European Commission – NextGenerationEU (Regulation EU 2020/2094), through CSIC’s\r\nQuantum Technologies Platform (QTEP). ICN2 is supported by the Severo Ochoa program from Spanish MCIN/AEI (Grant No.: CEX2021-001214-S) and is funded by the CERCA Programme/Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Autònoma de Barcelona Materials Science PhD program. AGM has received funding from Grant RYC2021-033479-I funded by MCIN/AEI/10.13039/501100011033 and by European Union NextGenerationEU/PRTR. M.B. acknowledges support from SUR Generalitat de Catalunya and the EU Social Fund; project ref. 2020 FI 00103. The authors\r\nacknowledge the use of instrumentation and the technical advice provided by the Joint Electron Microscopy Center at ALBA (JEMCA). ICN2 acknowledges funding from Grant IU16-014206 (METCAM-FIB) funded by the European Union through the European Regional Development\r\nFund (ERDF), with the support of the Ministry of Research and Universities, Generalitat de Catalunya. ICN2 is a founding member of e-DREAM [60]." article_number: '2407.03079' article_processing_charge: No arxiv: 1 author: - first_name: Marian full_name: Janik, Marian id: 396A1950-F248-11E8-B48F-1D18A9856A87 last_name: Janik orcid: 0009-0003-9037-8831 - first_name: Kevin Etienne Robert full_name: Roux, Kevin Etienne Robert id: 53f93ea2-803f-11ed-ab7e-b283135794ef last_name: Roux - first_name: Carla N full_name: Borja Espinosa, Carla N id: 18777c01-896a-11ed-bdf8-e4851dc07d16 last_name: Borja Espinosa - first_name: Oliver full_name: Sagi, Oliver id: 71616374-A8E9-11E9-A7CA-09ECE5697425 last_name: Sagi - first_name: Abdulhamid full_name: Baghdadi, Abdulhamid id: 160D87FA-96B5-11E9-BF77-7626E6697425 last_name: Baghdadi - first_name: Thomas full_name: Adletzberger, Thomas id: 38756BB2-F248-11E8-B48F-1D18A9856A87 last_name: Adletzberger - first_name: Stefano full_name: Calcaterra, Stefano last_name: Calcaterra - first_name: Marc full_name: Botifoll, Marc last_name: Botifoll - first_name: Alba Garzón full_name: Manjón, Alba Garzón last_name: Manjón - first_name: Jordi full_name: Arbiol, Jordi last_name: Arbiol - first_name: Daniel full_name: Chrastina, Daniel last_name: Chrastina - first_name: Giovanni full_name: Isella, Giovanni last_name: Isella - first_name: Ioan M. full_name: Pop, Ioan M. last_name: Pop - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Janik M, Roux KER, Borja Espinosa CN, et al. Strong charge-photon coupling in planar germanium enabled by granular  aluminium superinductors. arXiv. doi:10.48550/arXiv.2407.03079 apa: Janik, M., Roux, K. E. R., Borja Espinosa, C. N., Sagi, O., Baghdadi, A., Adletzberger, T., … Katsaros, G. (n.d.). Strong charge-photon coupling in planar germanium enabled by granular  aluminium superinductors. arXiv. https://doi.org/10.48550/arXiv.2407.03079 chicago: Janik, Marian, Kevin Etienne Robert Roux, Carla N Borja Espinosa, Oliver Sagi, Abdulhamid Baghdadi, Thomas Adletzberger, Stefano Calcaterra, et al. “Strong Charge-Photon Coupling in Planar Germanium Enabled by Granular  Aluminium Superinductors.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2407.03079. ieee: M. Janik et al., “Strong charge-photon coupling in planar germanium enabled by granular  aluminium superinductors,” arXiv. . ista: Janik M, Roux KER, Borja Espinosa CN, Sagi O, Baghdadi A, Adletzberger T, Calcaterra S, Botifoll M, Manjón AG, Arbiol J, Chrastina D, Isella G, Pop IM, Katsaros G. Strong charge-photon coupling in planar germanium enabled by granular  aluminium superinductors. arXiv, 2407.03079. mla: Janik, Marian, et al. “Strong Charge-Photon Coupling in Planar Germanium Enabled by Granular  Aluminium Superinductors.” ArXiv, 2407.03079, doi:10.48550/arXiv.2407.03079. short: M. Janik, K.E.R. Roux, C.N. Borja Espinosa, O. Sagi, A. Baghdadi, T. Adletzberger, S. Calcaterra, M. Botifoll, A.G. Manjón, J. Arbiol, D. Chrastina, G. Isella, I.M. Pop, G. Katsaros, ArXiv (n.d.). corr_author: '1' date_created: 2024-09-26T09:50:43Z date_published: 2024-07-03T00:00:00Z date_updated: 2026-05-29T22:30:24Z day: '03' department: - _id: GeKa - _id: GradSch - _id: JoFi doi: 10.48550/arXiv.2407.03079 external_id: arxiv: - '2407.03079' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2407.03079 month: '07' oa: 1 oa_version: Preprint project: - _id: 34c0acea-11ca-11ed-8bc3-8775e10fd452 grant_number: '101069515' name: Integrated Germanium Quantum Technology - _id: 237B3DA4-32DE-11EA-91FC-C7463DDC885E call_identifier: FWF grant_number: P32235 name: Towards scalable hut wire quantum devices - _id: bd8bd29e-d553-11ed-ba76-f0070d4b237a grant_number: P36507 name: Merging spin and superconducting qubits in planar Ge - _id: c0977eea-5a5b-11eb-8a69-a862db0cf4d1 grant_number: I05060 name: High impedance circuit quantum electrodynamics with hole spins publication: arXiv publication_status: draft related_material: record: - id: '18886' relation: research_data status: public - id: '19401' relation: later_version status: public - id: '18129' relation: dissertation_contains status: public status: public title: Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2024' ... --- OA_place: repository _id: '13312' abstract: - lang: eng 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." acknowledged_ssus: - _id: M-Shop - _id: NanoFab 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." article_number: '2306.07109' article_processing_charge: No arxiv: 1 author: - first_name: Marco full_name: Valentini, Marco id: C0BB2FAC-D767-11E9-B658-BC13E6697425 last_name: Valentini - first_name: Oliver full_name: Sagi, Oliver id: 71616374-A8E9-11E9-A7CA-09ECE5697425 last_name: Sagi - first_name: Levon full_name: Baghumyan, Levon last_name: Baghumyan - first_name: Thijs de full_name: Gijsel, Thijs de last_name: Gijsel - first_name: Jason full_name: Jung, Jason id: 4C9ACE7A-F248-11E8-B48F-1D18A9856A87 last_name: Jung - first_name: Stefano full_name: Calcaterra, Stefano last_name: Calcaterra - first_name: Andrea full_name: Ballabio, Andrea last_name: Ballabio - first_name: Juan Aguilera full_name: Servin, Juan Aguilera last_name: Servin - first_name: Kushagra full_name: Aggarwal, Kushagra id: b22ab905-3539-11eb-84c3-fc159dcd79cb last_name: Aggarwal orcid: 0000-0001-9985-9293 - first_name: Marian full_name: Janik, Marian id: 396A1950-F248-11E8-B48F-1D18A9856A87 last_name: Janik orcid: 0009-0003-9037-8831 - first_name: Thomas full_name: Adletzberger, Thomas id: 38756BB2-F248-11E8-B48F-1D18A9856A87 last_name: Adletzberger - first_name: Rubén Seoane full_name: Souto, Rubén Seoane last_name: Souto - first_name: Martin full_name: Leijnse, Martin last_name: Leijnse - first_name: Jeroen full_name: Danon, Jeroen last_name: Danon - first_name: Constantin full_name: Schrade, Constantin last_name: Schrade - first_name: Erik full_name: Bakkers, Erik last_name: Bakkers - first_name: Daniel full_name: Chrastina, Daniel last_name: Chrastina - first_name: Giovanni full_name: Isella, Giovanni last_name: Isella - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: 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. arXiv. doi:10.48550/arXiv.2306.07109 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. arXiv. https://doi.org/10.48550/arXiv.2306.07109 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.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2306.07109. ieee: M. Valentini et al., “Radio frequency driven superconducting diode and parity conserving  Cooper pair transport in a two-dimensional germanium hole gas,” arXiv. . 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. mla: Valentini, Marco, et al. “Radio Frequency Driven Superconducting Diode and Parity Conserving  Cooper Pair Transport in a Two-Dimensional Germanium Hole Gas.” ArXiv, 2306.07109, doi:10.48550/arXiv.2306.07109. 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.). corr_author: '1' date_created: 2023-07-26T11:17:20Z date_published: 2023-06-13T00:00:00Z date_updated: 2026-04-07T13:27:22Z day: '13' ddc: - '530' department: - _id: GeKa - _id: M-Shop doi: 10.48550/arXiv.2306.07109 ec_funded: 1 external_id: arxiv: - '2306.07109' keyword: - Mesoscale and Nanoscale Physics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2306.07109 month: '06' oa: 1 oa_version: Preprint project: - _id: 237E5020-32DE-11EA-91FC-C7463DDC885E call_identifier: H2020 grant_number: '862046' name: TOPOLOGICALLY PROTECTED AND SCALABLE QUANTUM BITS - _id: 237B3DA4-32DE-11EA-91FC-C7463DDC885E call_identifier: FWF grant_number: P32235 name: Towards scalable hut wire quantum devices - _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' - _id: eb9b30ac-77a9-11ec-83b8-871f581d53d2 name: Protected states of quantum matter publication: arXiv publication_status: draft related_material: record: - id: '13286' relation: dissertation_contains status: public status: public title: Radio frequency driven superconducting diode and parity conserving Cooper pair transport in a two-dimensional germanium hole gas tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2023' ...