--- _id: '10920' abstract: - lang: eng text: The spin-orbit interaction permits to control the state of a spin qubit via electric fields. For holes it is particularly strong, allowing for fast all electrical qubit manipulation, and yet an in-depth understanding of this interaction in hole systems is missing. Here we investigate, experimentally and theoretically, the effect of the cubic Rashba spin-orbit interaction on the mixing of the spin states by studying singlet-triplet oscillations in a planar Ge hole double quantum dot. Landau-Zener sweeps at different magnetic field directions allow us to disentangle the effects of the spin-orbit induced spin-flip term from those caused by strongly site-dependent and anisotropic quantum dot g tensors. Our work, therefore, provides new insights into the hole spin-orbit interaction, necessary for optimizing future qubit experiments. acknowledged_ssus: - _id: M-Shop - _id: NanoFab acknowledgement: "This research was supported by the Scientific Service Units of ISTA through resources provided by the MIBA Machine Shop and the nanofabrication facility. This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie\r\nSkłodowska-Curie Grant Agreement No. 844511, No. 75441, and by the FWF-P 30207, I05060, and M3032-N projects. A. B. acknowledges support from the EU Horizon-2020 FET project microSPIRE, ID: 766955. P.M. M. and G. B. acknowledge funding by the Deutsche Forschungsgemeinschaft (DFG—German Research Foundation) under Project No. 450396347. This work was supported by the Royal Society (URF\\R1\\191150) and the European Research Council (Grant Agreement No. 948932), N. A. acknowledges the use of the University of Oxford Advanced Research Computing (ARC) facility." article_number: '126803' article_processing_charge: No article_type: original author: - first_name: Daniel full_name: Jirovec, Daniel id: 4C473F58-F248-11E8-B48F-1D18A9856A87 last_name: Jirovec orcid: 0000-0002-7197-4801 - first_name: Philipp M. full_name: Mutter, Philipp M. last_name: Mutter - first_name: Andrea C full_name: Hofmann, Andrea C id: 340F461A-F248-11E8-B48F-1D18A9856A87 last_name: Hofmann - first_name: Alessandro full_name: Crippa, Alessandro id: 1F2B21A2-F6E7-11E9-9B82-F7DBE5697425 last_name: Crippa orcid: 0000-0002-2968-611X - first_name: Marek full_name: Rychetsky, Marek last_name: Rychetsky - first_name: David L. full_name: Craig, David L. last_name: Craig - first_name: Josip full_name: Kukucka, Josip id: 3F5D8856-F248-11E8-B48F-1D18A9856A87 last_name: Kukucka - first_name: Frederico full_name: Martins, Frederico id: 38F80F9A-1CB8-11EA-BC76-B49B3DDC885E last_name: Martins orcid: 0000-0003-2668-2401 - first_name: Andrea full_name: Ballabio, Andrea last_name: Ballabio - first_name: Natalia full_name: Ares, Natalia last_name: Ares - first_name: Daniel full_name: Chrastina, Daniel last_name: Chrastina - first_name: Giovanni full_name: Isella, Giovanni last_name: Isella - first_name: 'Guido ' full_name: 'Burkard, Guido ' last_name: Burkard - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros citation: ama: Jirovec D, Mutter PM, Hofmann AC, et al. Dynamics of hole singlet-triplet qubits with large g-factor differences. Physical Review Letters. 2022;128(12). doi:10.1103/PhysRevLett.128.126803 apa: Jirovec, D., Mutter, P. M., Hofmann, A. C., Crippa, A., Rychetsky, M., Craig, D. L., … Katsaros, G. (2022). Dynamics of hole singlet-triplet qubits with large g-factor differences. Physical Review Letters. American Physical Society. https://doi.org/10.1103/PhysRevLett.128.126803 chicago: Jirovec, Daniel, Philipp M. Mutter, Andrea C Hofmann, Alessandro Crippa, Marek Rychetsky, David L. Craig, Josip Kukucka, et al. “Dynamics of Hole Singlet-Triplet Qubits with Large g-Factor Differences.” Physical Review Letters. American Physical Society, 2022. https://doi.org/10.1103/PhysRevLett.128.126803. ieee: D. Jirovec et al., “Dynamics of hole singlet-triplet qubits with large g-factor differences,” Physical Review Letters, vol. 128, no. 12. American Physical Society, 2022. ista: Jirovec D, Mutter PM, Hofmann AC, Crippa A, Rychetsky M, Craig DL, Kukucka J, Martins F, Ballabio A, Ares N, Chrastina D, Isella G, Burkard G, Katsaros G. 2022. Dynamics of hole singlet-triplet qubits with large g-factor differences. Physical Review Letters. 128(12), 126803. mla: Jirovec, Daniel, et al. “Dynamics of Hole Singlet-Triplet Qubits with Large g-Factor Differences.” Physical Review Letters, vol. 128, no. 12, 126803, American Physical Society, 2022, doi:10.1103/PhysRevLett.128.126803. short: D. Jirovec, P.M. Mutter, A.C. Hofmann, A. Crippa, M. Rychetsky, D.L. Craig, J. Kukucka, F. Martins, A. Ballabio, N. Ares, D. Chrastina, G. Isella, G. Burkard, G. Katsaros, Physical Review Letters 128 (2022). date_created: 2022-03-24T15:51:11Z date_published: 2022-03-24T00:00:00Z date_updated: 2023-08-03T06:14:58Z day: '24' ddc: - '530' department: - _id: GradSch - _id: GeKa doi: 10.1103/PhysRevLett.128.126803 ec_funded: 1 external_id: arxiv: - '2111.05130' isi: - '000786542500004' file: - access_level: open_access checksum: 6e66ad548d18db9c131f304acbd5a1f4 content_type: application/pdf creator: dernst date_created: 2022-03-28T06:53:39Z date_updated: 2022-03-28T06:53:39Z file_id: '10928' file_name: 2022_PhysRevLetters_Jirovec.pdf file_size: 1266515 relation: main_file success: 1 file_date_updated: 2022-03-28T06:53:39Z has_accepted_license: '1' intvolume: ' 128' isi: 1 issue: '12' language: - iso: eng month: '03' oa: 1 oa_version: Published Version project: - _id: 26A151DA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '844511' name: Majorana bound states in Ge/SiGe heterostructures - _id: 260C2330-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '754411' name: ISTplus - Postdoctoral Fellowships - _id: 2641CE5E-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P30207 name: Hole spin orbit qubits in Ge quantum wells - _id: c0977eea-5a5b-11eb-8a69-a862db0cf4d1 grant_number: I05060 name: High impedance circuit quantum electrodynamics with hole spins - _id: c08c05c4-5a5b-11eb-8a69-dc6ce49d7973 grant_number: M03032 name: Long-range spin exchange for 2D qubits architectures publication: Physical Review Letters publication_identifier: eissn: - 1079-7114 publication_status: published publisher: American Physical Society quality_controlled: '1' status: public title: Dynamics of hole singlet-triplet qubits with large g-factor differences 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: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 128 year: '2022' ... --- _id: '9323' abstract: - lang: eng text: This .zip File contains the data for figures presented in the main text and supplementary material of "A singlet triplet hole spin qubit in planar Ge" by D. Jirovec, et. al. The measurements were done using Labber Software and the data is stored in the hdf5 file format. The files can be opened using either the Labber Log Browser (https://labber.org/overview/) or Labber Python API (http://labber.org/online-doc/api/LogFile.html). A single file is acquired with QCodes and features the corresponding data type. XRD data are in .dat format and a code to open the data is provided. The code for simulations is as well provided in Python. article_processing_charge: No author: - first_name: Daniel full_name: Jirovec, Daniel id: 4C473F58-F248-11E8-B48F-1D18A9856A87 last_name: Jirovec orcid: 0000-0002-7197-4801 citation: ama: Jirovec D. Research data for “A singlet-triplet hole spin qubit planar Ge.” 2021. doi:10.15479/AT:ISTA:9323 apa: Jirovec, D. (2021). Research data for “A singlet-triplet hole spin qubit planar Ge.” Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:9323 chicago: Jirovec, Daniel. “Research Data for ‘A Singlet-Triplet Hole Spin Qubit Planar Ge.’” Institute of Science and Technology Austria, 2021. https://doi.org/10.15479/AT:ISTA:9323. ieee: D. Jirovec, “Research data for ‘A singlet-triplet hole spin qubit planar Ge.’” Institute of Science and Technology Austria, 2021. ista: Jirovec D. 2021. Research data for ‘A singlet-triplet hole spin qubit planar Ge’, Institute of Science and Technology Austria, 10.15479/AT:ISTA:9323. mla: Jirovec, Daniel. Research Data for “A Singlet-Triplet Hole Spin Qubit Planar Ge.” Institute of Science and Technology Austria, 2021, doi:10.15479/AT:ISTA:9323. short: D. Jirovec, (2021). contributor: - contributor_type: project_member first_name: Daniel id: 4C473F58-F248-11E8-B48F-1D18A9856A87 last_name: Jirovec date_created: 2021-04-14T09:50:22Z date_published: 2021-04-14T00:00:00Z date_updated: 2024-02-21T12:39:15Z day: '14' ddc: - '530' department: - _id: GradSch - _id: GeKa doi: 10.15479/AT:ISTA:9323 file: - access_level: open_access checksum: c569d2a2ce1694445cdbca19cf8ae023 content_type: application/x-zip-compressed creator: djirovec date_created: 2021-04-14T09:48:47Z date_updated: 2021-04-14T09:48:47Z file_id: '9324' file_name: DataRepositorySTqubit.zip file_size: 221832287 relation: main_file success: 1 - access_level: open_access checksum: 845bdf87430718ad6aff47eda7b5fc92 content_type: application/octet-stream creator: djirovec date_created: 2021-04-14T09:49:30Z date_updated: 2021-04-14T09:49:30Z file_id: '9325' file_name: ReadMe file_size: 4323 relation: main_file success: 1 file_date_updated: 2021-04-14T09:49:30Z has_accepted_license: '1' license: https://creativecommons.org/publicdomain/zero/1.0/ month: '04' oa: 1 oa_version: Published Version publisher: Institute of Science and Technology Austria related_material: record: - id: '8909' relation: used_in_publication status: public status: public title: Research data for "A singlet-triplet hole spin qubit planar Ge" tmp: image: /images/cc_0.png legal_code_url: https://creativecommons.org/publicdomain/zero/1.0/legalcode name: Creative Commons Public Domain Dedication (CC0 1.0) short: CC0 (1.0) type: research_data user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2021' ... --- _id: '10559' abstract: - lang: eng text: Hole gases in planar germanium can have high mobilities in combination with strong spin-orbit interaction and electrically tunable g factors, and are therefore emerging as a promising platform for creating hybrid superconductor-semiconductor devices. A key challenge towards hybrid Ge-based quantum technologies is the design of high-quality interfaces and superconducting contacts that are robust against magnetic fields. In this work, by combining the assets of aluminum, which provides good contact to the Ge, and niobium, which has a significant superconducting gap, we demonstrate highly transparent low-disordered JoFETs with relatively large ICRN products that are capable of withstanding high magnetic fields. We furthermore demonstrate the ability of phase-biasing individual JoFETs, opening up an avenue to explore topological superconductivity in planar Ge. The persistence of superconductivity in the reported hybrid devices beyond 1.8 T paves the way towards integrating spin qubits and proximity-induced superconductivity on the same chip. acknowledged_ssus: - _id: NanoFab - _id: M-Shop acknowledgement: This research and related results were made possible with the support of the NOMIS Foundation. This research was supported by the Scientific Service Units of IST Austria through resources provided by the MIBA Machine Shop and the nanofabrication facility, the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant agreement No. 844511 Grant Agreement No. 862046. ICN2 acknowledge funding from Generalitat de Catalunya 2017 SGR 327. ICN2 is supported by the Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706) and is funded by the CERCA Programme/Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Autnoma de Barcelona Materials Science PhD program. The HAADF-STEM microscopy was conducted in the Laboratorio de Microscopias Avanzadas at Instituto de Nanociencia de Aragon-Universidad de Zaragoza. Authors acknowledge the LMA-INA for offering access to their instruments and expertise. We acknowledge support from CSIC Research Platform on Quantum Technologies PTI-001. This project has received funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 823717 ESTEEM3. M.B. acknowledges support from SUR Generalitat de Catalunya and the EU Social Fund; project ref. 2020 FI 00103. G.S. and M.V. acknowledge support through a projectruimte grant associated with the Netherlands Organization of Scientific Research (NWO). J.D. acknowledges support through FRIPRO-project 274853, which is funded by the Research Council of Norway. article_number: L022005 article_processing_charge: No article_type: original author: - first_name: Kushagra full_name: Aggarwal, Kushagra id: b22ab905-3539-11eb-84c3-fc159dcd79cb last_name: Aggarwal orcid: 0000-0001-9985-9293 - first_name: Andrea C full_name: Hofmann, Andrea C id: 340F461A-F248-11E8-B48F-1D18A9856A87 last_name: Hofmann - first_name: Daniel full_name: Jirovec, Daniel id: 4C473F58-F248-11E8-B48F-1D18A9856A87 last_name: Jirovec orcid: 0000-0002-7197-4801 - first_name: Ivan full_name: Prieto Gonzalez, Ivan id: 2A307FE2-F248-11E8-B48F-1D18A9856A87 last_name: Prieto Gonzalez orcid: 0000-0002-7370-5357 - first_name: Amir full_name: Sammak, Amir last_name: Sammak - first_name: Marc full_name: Botifoll, Marc last_name: Botifoll - first_name: Sara full_name: Martí-Sánchez, Sara last_name: Martí-Sánchez - first_name: Menno full_name: Veldhorst, Menno last_name: Veldhorst - first_name: Jordi full_name: Arbiol, Jordi last_name: Arbiol - first_name: Giordano full_name: Scappucci, Giordano last_name: Scappucci - first_name: Jeroen full_name: Danon, Jeroen last_name: Danon - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Aggarwal K, Hofmann AC, Jirovec D, et al. Enhancement of proximity-induced superconductivity in a planar Ge hole gas. Physical Review Research. 2021;3(2). doi:10.1103/physrevresearch.3.l022005 apa: Aggarwal, K., Hofmann, A. C., Jirovec, D., Prieto Gonzalez, I., Sammak, A., Botifoll, M., … Katsaros, G. (2021). Enhancement of proximity-induced superconductivity in a planar Ge hole gas. Physical Review Research. American Physical Society. https://doi.org/10.1103/physrevresearch.3.l022005 chicago: Aggarwal, Kushagra, Andrea C Hofmann, Daniel Jirovec, Ivan Prieto Gonzalez, Amir Sammak, Marc Botifoll, Sara Martí-Sánchez, et al. “Enhancement of Proximity-Induced Superconductivity in a Planar Ge Hole Gas.” Physical Review Research. American Physical Society, 2021. https://doi.org/10.1103/physrevresearch.3.l022005. ieee: K. Aggarwal et al., “Enhancement of proximity-induced superconductivity in a planar Ge hole gas,” Physical Review Research, vol. 3, no. 2. American Physical Society, 2021. ista: Aggarwal K, Hofmann AC, Jirovec D, Prieto Gonzalez I, Sammak A, Botifoll M, Martí-Sánchez S, Veldhorst M, Arbiol J, Scappucci G, Danon J, Katsaros G. 2021. Enhancement of proximity-induced superconductivity in a planar Ge hole gas. Physical Review Research. 3(2), L022005. mla: Aggarwal, Kushagra, et al. “Enhancement of Proximity-Induced Superconductivity in a Planar Ge Hole Gas.” Physical Review Research, vol. 3, no. 2, L022005, American Physical Society, 2021, doi:10.1103/physrevresearch.3.l022005. short: K. Aggarwal, A.C. Hofmann, D. Jirovec, I. Prieto Gonzalez, A. Sammak, M. Botifoll, S. Martí-Sánchez, M. Veldhorst, J. Arbiol, G. Scappucci, J. Danon, G. Katsaros, Physical Review Research 3 (2021). date_created: 2021-12-16T18:50:57Z date_published: 2021-04-15T00:00:00Z date_updated: 2024-02-21T12:41:26Z day: '15' ddc: - '620' department: - _id: GeKa doi: 10.1103/physrevresearch.3.l022005 ec_funded: 1 external_id: arxiv: - '2012.00322' file: - access_level: open_access checksum: 60a1bc9c9b616b1b155044bb8cfc6484 content_type: application/pdf creator: cchlebak date_created: 2021-12-17T08:12:37Z date_updated: 2021-12-17T08:12:37Z file_id: '10561' file_name: 2021_PhysRevResearch_Aggarwal.pdf file_size: 1917512 relation: main_file success: 1 file_date_updated: 2021-12-17T08:12:37Z has_accepted_license: '1' intvolume: ' 3' issue: '2' keyword: - general engineering language: - iso: eng month: '04' oa: 1 oa_version: Published Version project: - _id: 26A151DA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '844511' name: Majorana bound states in Ge/SiGe heterostructures - _id: 237E5020-32DE-11EA-91FC-C7463DDC885E call_identifier: H2020 grant_number: '862046' name: TOPOLOGICALLY PROTECTED AND SCALABLE QUANTUM BITS publication: Physical Review Research publication_identifier: issn: - 2643-1564 publication_status: published publisher: American Physical Society quality_controlled: '1' related_material: record: - id: '8831' relation: earlier_version status: public - id: '8834' relation: research_data status: public scopus_import: '1' status: public title: Enhancement of proximity-induced superconductivity in a planar Ge 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: journal_article user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 volume: 3 year: '2021' ... --- _id: '10058' abstract: - lang: eng text: 'Quantum information and computation has become a vast field paved with opportunities for researchers and investors. As large multinational companies and international funds are heavily investing in quantum technologies it is still a question which platform is best suited for the task of realizing a scalable quantum processor. In this work we investigate hole spins in Ge quantum wells. These hold great promise as they possess several favorable properties: a small effective mass, a strong spin-orbit coupling, long relaxation time and an inherent immunity to hyperfine noise. All these characteristics helped Ge hole spin qubits to evolve from a single qubit to a fully entangled four qubit processor in only 3 years. Here, we investigated a qubit approach leveraging the large out-of-plane g-factors of heavy hole states in Ge quantum dots. We found this qubit to be reproducibly operable at extremely low magnetic field and at large speeds while maintaining coherence. This was possible because large differences of g-factors in adjacent dots can be achieved in the out-of-plane direction. In the in-plane direction the small g-factors, on the other hand, can be altered very effectively by the confinement potentials. Here, we found that this can even lead to a sign change of the g-factors. The resulting g-factor difference alters the dynamics of the system drastically and produces effects typically attributed to a spin-orbit induced spin-flip term. The investigations carried out in this thesis give further insights into the possibilities of holes in Ge and reveal new physical properties that need to be considered when designing future spin qubit experiments.' acknowledged_ssus: - _id: M-Shop - _id: NanoFab acknowledgement: The author gratefully acknowledges support by the Austrian Science Fund (FWF), grants No P30207, and the Nomis foundation. alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Daniel full_name: Jirovec, Daniel id: 4C473F58-F248-11E8-B48F-1D18A9856A87 last_name: Jirovec orcid: 0000-0002-7197-4801 citation: ama: Jirovec D. Singlet-Triplet qubits and spin-orbit interaction in 2-dimensional Ge hole gases. 2021. doi:10.15479/at:ista:10058 apa: Jirovec, D. (2021). Singlet-Triplet qubits and spin-orbit interaction in 2-dimensional Ge hole gases. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:10058 chicago: Jirovec, Daniel. “Singlet-Triplet Qubits and Spin-Orbit Interaction in 2-Dimensional Ge Hole Gases.” Institute of Science and Technology Austria, 2021. https://doi.org/10.15479/at:ista:10058. ieee: D. Jirovec, “Singlet-Triplet qubits and spin-orbit interaction in 2-dimensional Ge hole gases,” Institute of Science and Technology Austria, 2021. ista: Jirovec D. 2021. Singlet-Triplet qubits and spin-orbit interaction in 2-dimensional Ge hole gases. Institute of Science and Technology Austria. mla: Jirovec, Daniel. Singlet-Triplet Qubits and Spin-Orbit Interaction in 2-Dimensional Ge Hole Gases. Institute of Science and Technology Austria, 2021, doi:10.15479/at:ista:10058. short: D. Jirovec, Singlet-Triplet Qubits and Spin-Orbit Interaction in 2-Dimensional Ge Hole Gases, Institute of Science and Technology Austria, 2021. date_created: 2021-09-30T07:53:49Z date_published: 2021-10-05T00:00:00Z date_updated: 2023-09-08T11:41:08Z day: '05' ddc: - '621' - '539' degree_awarded: PhD department: - _id: GradSch - _id: GeKa doi: 10.15479/at:ista:10058 file: - access_level: closed checksum: ad6bcb24083ed7c02baaf1885c9ea3d5 content_type: application/x-zip-compressed creator: djirovec date_created: 2021-09-30T14:29:14Z date_updated: 2022-12-20T23:30:07Z embargo_to: open_access file_id: '10061' file_name: PHD_Thesis_Jirovec_Source.zip file_size: 32397600 relation: source_file - access_level: open_access checksum: 5fbe08d4f66d1153e04c47971538fae8 content_type: application/pdf creator: djirovec date_created: 2021-10-05T07:56:49Z date_updated: 2022-12-20T23:30:07Z embargo: 2022-10-06 file_id: '10087' file_name: PHD_Thesis_pdfa2b_1.pdf file_size: 26910829 relation: main_file file_date_updated: 2022-12-20T23:30:07Z has_accepted_license: '1' keyword: - qubits - quantum computing - holes language: - iso: eng month: '10' oa: 1 oa_version: Published Version page: '151' project: - _id: 2641CE5E-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P30207 name: Hole spin orbit qubits in Ge quantum wells publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '8831' relation: part_of_dissertation status: public - id: '10065' relation: part_of_dissertation status: public - id: '10066' relation: part_of_dissertation status: public - id: '8909' relation: part_of_dissertation status: public - id: '5816' 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: Singlet-Triplet qubits and spin-orbit interaction in 2-dimensional Ge hole gases 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: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2021' ... --- _id: '8909' abstract: - lang: eng text: Spin qubits are considered to be among the most promising candidates for building a quantum processor. Group IV hole spin qubits have moved into the focus of interest due to the ease of operation and compatibility with Si technology. In addition, Ge offers the option for monolithic superconductor-semiconductor integration. Here we demonstrate a hole spin qubit operating at fields below 10 mT, the critical field of Al, by exploiting the large out-of-plane hole g-factors in planar Ge and by encoding the qubit into the singlet-triplet states of a double quantum dot. We observe electrically controlled X and Z-rotations with tunable frequencies exceeding 100 MHz and dephasing times of 1μs which we extend beyond 15μs with echo techniques. These results show that Ge hole singlet triplet qubits outperform their electronic Si and GaAs based counterparts in speed and coherence, respectively. In addition, they are on par with Ge single spin qubits, but can be operated at much lower fields underlining their potential for on chip integration with superconducting technologies. acknowledged_ssus: - _id: M-Shop - _id: NanoFab acknowledgement: This research was supported by the Scientific Service Units of Institute of Science and Technology (IST) Austria through resources provided by the Miba Machine Shop and the nanofabrication facility, and was made possible with the support of the NOMIS Foundation. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreements no. 844511 and no. 75441, and by the Austrian Science Fund FWF-P 30207 project. A.B. acknowledges support from the European Union Horizon 2020 FET project microSPIRE, no. 766955. M. Botifoll and J.A. acknowledge funding from Generalitat de Catalunya 2017 SGR 327. The Catalan Institute of Nanoscience and Nanotechnology (ICN2) is supported by the Severo Ochoa programme from the Spanish Ministery of Economy (MINECO) (grant no. SEV-2017-0706) and is funded by the Catalonian Research Centre (CERCA) Programme, Generalitat de Catalunya. Part of the present work has been performed within the framework of the Universitat Autónoma de Barcelona Materials Science PhD programme. Part of the HAADF scanning transmission electron microscopy was conducted in the Laboratorio de Microscopias Avanzadas at Instituto de Nanociencia de Aragon, Universidad de Zaragoza. ICN2 acknowledge support from the Spanish Superior Council of Scientific Research (CSIC) Research Platform on Quantum Technologies PTI-001. M.B. acknowledges funding from the Catalan Agency for Management of University and Research Grants (AGAUR) Generalitat de Catalunya formation of investigators (FI) PhD grant. article_processing_charge: No article_type: original author: - first_name: Daniel full_name: Jirovec, Daniel id: 4C473F58-F248-11E8-B48F-1D18A9856A87 last_name: Jirovec orcid: 0000-0002-7197-4801 - first_name: Andrea C full_name: Hofmann, Andrea C id: 340F461A-F248-11E8-B48F-1D18A9856A87 last_name: Hofmann - first_name: Andrea full_name: Ballabio, Andrea last_name: Ballabio - first_name: Philipp M. full_name: Mutter, Philipp M. last_name: Mutter - first_name: Giulio full_name: Tavani, Giulio last_name: Tavani - first_name: Marc full_name: Botifoll, Marc last_name: Botifoll - first_name: Alessandro full_name: Crippa, Alessandro id: 1F2B21A2-F6E7-11E9-9B82-F7DBE5697425 last_name: Crippa orcid: 0000-0002-2968-611X - first_name: Josip full_name: Kukucka, Josip id: 3F5D8856-F248-11E8-B48F-1D18A9856A87 last_name: Kukucka - first_name: Oliver full_name: Sagi, Oliver id: 71616374-A8E9-11E9-A7CA-09ECE5697425 last_name: Sagi - first_name: Frederico full_name: Martins, Frederico id: 38F80F9A-1CB8-11EA-BC76-B49B3DDC885E last_name: Martins orcid: 0000-0003-2668-2401 - first_name: Jaime full_name: Saez Mollejo, Jaime id: e0390f72-f6e0-11ea-865d-862393336714 last_name: Saez Mollejo - first_name: Ivan full_name: Prieto Gonzalez, Ivan id: 2A307FE2-F248-11E8-B48F-1D18A9856A87 last_name: Prieto Gonzalez orcid: 0000-0002-7370-5357 - first_name: Maksim full_name: Borovkov, Maksim id: 2ac7a0a2-3562-11eb-9256-fbd18ea55087 last_name: Borovkov - 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: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Jirovec D, Hofmann AC, Ballabio A, et al. A singlet triplet hole spin qubit in planar Ge. Nature Materials. 2021;20(8):1106–1112. doi:10.1038/s41563-021-01022-2 apa: Jirovec, D., Hofmann, A. C., Ballabio, A., Mutter, P. M., Tavani, G., Botifoll, M., … Katsaros, G. (2021). A singlet triplet hole spin qubit in planar Ge. Nature Materials. Springer Nature. https://doi.org/10.1038/s41563-021-01022-2 chicago: Jirovec, Daniel, Andrea C Hofmann, Andrea Ballabio, Philipp M. Mutter, Giulio Tavani, Marc Botifoll, Alessandro Crippa, et al. “A Singlet Triplet Hole Spin Qubit in Planar Ge.” Nature Materials. Springer Nature, 2021. https://doi.org/10.1038/s41563-021-01022-2. ieee: D. Jirovec et al., “A singlet triplet hole spin qubit in planar Ge,” Nature Materials, vol. 20, no. 8. Springer Nature, pp. 1106–1112, 2021. ista: Jirovec D, Hofmann AC, Ballabio A, Mutter PM, Tavani G, Botifoll M, Crippa A, Kukucka J, Sagi O, Martins F, Saez Mollejo J, Prieto Gonzalez I, Borovkov M, Arbiol J, Chrastina D, Isella G, Katsaros G. 2021. A singlet triplet hole spin qubit in planar Ge. Nature Materials. 20(8), 1106–1112. mla: Jirovec, Daniel, et al. “A Singlet Triplet Hole Spin Qubit in Planar Ge.” Nature Materials, vol. 20, no. 8, Springer Nature, 2021, pp. 1106–1112, doi:10.1038/s41563-021-01022-2. short: D. Jirovec, A.C. Hofmann, A. Ballabio, P.M. Mutter, G. Tavani, M. Botifoll, A. Crippa, J. Kukucka, O. Sagi, F. Martins, J. Saez Mollejo, I. Prieto Gonzalez, M. Borovkov, J. Arbiol, D. Chrastina, G. Isella, G. Katsaros, Nature Materials 20 (2021) 1106–1112. date_created: 2020-12-02T10:50:47Z date_published: 2021-08-01T00:00:00Z date_updated: 2024-03-28T23:30:27Z day: '01' department: - _id: GeKa - _id: NanoFab - _id: GradSch doi: 10.1038/s41563-021-01022-2 ec_funded: 1 external_id: arxiv: - '2011.13755' isi: - '000657596400001' intvolume: ' 20' isi: 1 issue: '8' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/2011.13755 month: '08' oa: 1 oa_version: Preprint page: 1106–1112 project: - _id: 26A151DA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '844511' name: Majorana bound states in Ge/SiGe heterostructures - _id: 260C2330-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '754411' name: ISTplus - Postdoctoral Fellowships - _id: 2641CE5E-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P30207 name: Hole spin orbit qubits in Ge quantum wells - _id: 262116AA-B435-11E9-9278-68D0E5697425 name: Hybrid Semiconductor - Superconductor Quantum Devices publication: Nature Materials publication_identifier: eissn: - 1476-4660 issn: - 1476-1122 publication_status: published publisher: Springer Nature quality_controlled: '1' related_material: link: - description: News on IST Homepage relation: press_release url: https://ist.ac.at/en/news/quantum-computing-with-holes/ record: - id: '9323' relation: research_data status: public - id: '10058' relation: dissertation_contains status: public scopus_import: '1' status: public title: A singlet triplet hole spin qubit in planar Ge type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 20 year: '2021' ... --- _id: '10066' abstract: - lang: eng text: The potential of Si and SiGe-based devices for the scaling of quantum circuits is tainted by device variability. Each device needs to be tuned to operation conditions. We give a key step towards tackling this variability with an algorithm that, without modification, is capable of tuning a 4-gate Si FinFET, a 5-gate GeSi nanowire and a 7-gate SiGe heterostructure double quantum dot device from scratch. We achieve tuning times of 30, 10, and 92 minutes, respectively. The algorithm also provides insight into the parameter space landscape for each of these devices. These results show that overarching solutions for the tuning of quantum devices are enabled by machine learning. acknowledged_ssus: - _id: NanoFab acknowledgement: "We acknowledge Ang Li, Erik P. A. M. Bakkers (University of Eindhoven) for the fabrication of the Ge/Si nanowire. This work was supported by the Royal Society, the EPSRC National Quantum Technology Hub in Networked Quantum Information Technology (EP/M013243/1), Quantum Technology Capital (EP/N014995/1), EPSRC Platform Grant\r\n(EP/R029229/1), the European Research Council (Grant agreement 948932), the Swiss Nanoscience Institute, the\r\nNCCR SPIN, the EU H2020 European Microkelvin Platform EMP grant No. 824109, the Scientific Service Units\r\nof IST Austria through resources provided by the nanofabrication facility and, the FWF-P30207 project. This publication was also made possible through support from Templeton World Charity Foundation and John Templeton Foundation. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the Templeton Foundations." article_number: '2107.12975' article_processing_charge: No author: - first_name: B. full_name: Severin, B. last_name: Severin - first_name: D. T. full_name: Lennon, D. T. last_name: Lennon - first_name: L. C. full_name: Camenzind, L. C. last_name: Camenzind - first_name: F. full_name: Vigneau, F. last_name: Vigneau - first_name: F. full_name: Fedele, F. last_name: Fedele - first_name: Daniel full_name: Jirovec, Daniel id: 4C473F58-F248-11E8-B48F-1D18A9856A87 last_name: Jirovec orcid: 0000-0002-7197-4801 - first_name: A. full_name: Ballabio, A. last_name: Ballabio - first_name: D. full_name: Chrastina, D. last_name: Chrastina - first_name: G. full_name: Isella, G. last_name: Isella - first_name: M. de full_name: Kruijf, M. de last_name: Kruijf - first_name: M. J. full_name: Carballido, M. J. last_name: Carballido - first_name: S. full_name: Svab, S. last_name: Svab - first_name: A. V. full_name: Kuhlmann, A. V. last_name: Kuhlmann - first_name: F. R. full_name: Braakman, F. R. last_name: Braakman - first_name: S. full_name: Geyer, S. last_name: Geyer - first_name: F. N. M. full_name: Froning, F. N. M. last_name: Froning - first_name: H. full_name: Moon, H. last_name: Moon - first_name: M. A. full_name: Osborne, M. A. last_name: Osborne - first_name: D. full_name: Sejdinovic, D. last_name: Sejdinovic - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X - first_name: D. M. full_name: Zumbühl, D. M. last_name: Zumbühl - first_name: G. A. D. full_name: Briggs, G. A. D. last_name: Briggs - first_name: N. full_name: Ares, N. last_name: Ares citation: ama: Severin B, Lennon DT, Camenzind LC, et al. Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning. arXiv. doi:10.48550/arXiv.2107.12975 apa: Severin, B., Lennon, D. T., Camenzind, L. C., Vigneau, F., Fedele, F., Jirovec, D., … Ares, N. (n.d.). Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning. arXiv. https://doi.org/10.48550/arXiv.2107.12975 chicago: Severin, B., D. T. Lennon, L. C. Camenzind, F. Vigneau, F. Fedele, Daniel Jirovec, A. Ballabio, et al. “Cross-Architecture Tuning of Silicon and SiGe-Based Quantum Devices Using Machine Learning.” ArXiv, n.d. https://doi.org/10.48550/arXiv.2107.12975. ieee: B. Severin et al., “Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning,” arXiv. . ista: Severin B, Lennon DT, Camenzind LC, Vigneau F, Fedele F, Jirovec D, Ballabio A, Chrastina D, Isella G, Kruijf M de, Carballido MJ, Svab S, Kuhlmann AV, Braakman FR, Geyer S, Froning FNM, Moon H, Osborne MA, Sejdinovic D, Katsaros G, Zumbühl DM, Briggs GAD, Ares N. Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning. arXiv, 2107.12975. mla: Severin, B., et al. “Cross-Architecture Tuning of Silicon and SiGe-Based Quantum Devices Using Machine Learning.” ArXiv, 2107.12975, doi:10.48550/arXiv.2107.12975. short: B. Severin, D.T. Lennon, L.C. Camenzind, F. Vigneau, F. Fedele, D. Jirovec, A. Ballabio, D. Chrastina, G. Isella, M. de Kruijf, M.J. Carballido, S. Svab, A.V. Kuhlmann, F.R. Braakman, S. Geyer, F.N.M. Froning, H. Moon, M.A. Osborne, D. Sejdinovic, G. Katsaros, D.M. Zumbühl, G.A.D. Briggs, N. Ares, ArXiv (n.d.). date_created: 2021-10-01T12:40:22Z date_published: 2021-07-27T00:00:00Z date_updated: 2024-03-28T23:30:27Z day: '27' department: - _id: GeKa doi: 10.48550/arXiv.2107.12975 external_id: arxiv: - '2107.12975' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2107.12975 month: '07' oa: 1 oa_version: Preprint project: - _id: 2641CE5E-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P30207 name: Hole spin orbit qubits in Ge quantum wells publication: arXiv publication_status: submitted related_material: record: - id: '10058' relation: dissertation_contains status: public status: public title: Cross-architecture tuning of silicon and SiGe-based quantum devices using machine learning type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2021' ... --- _id: '8831' abstract: - lang: eng text: Holes in planar Ge have high mobilities, strong spin-orbit interaction and electrically tunable g-factors, and are therefore emerging as a promising candidate for hybrid superconductorsemiconductor devices. This is further motivated by the observation of supercurrent transport in planar Ge Josephson Field effect transistors (JoFETs). A key challenge towards hybrid germanium quantum technology is the design of high quality interfaces and superconducting contacts that are robust against magnetic fields. By combining the assets of Al, which has a long superconducting coherence, and Nb, which has a significant superconducting gap, we form low-disordered JoFETs with large ICRN products that are capable of withstanding high magnetic fields. We furthermore demonstrate the ability of phase-biasing individual JoFETs opening up an avenue to explore topological superconductivity in planar Ge. The persistence of superconductivity in the reported hybrid devices beyond 1.8 T paves the way towards integrating spin qubits and proximity-induced superconductivity on the same chip. acknowledged_ssus: - _id: M-Shop - _id: NanoFab acknowledgement: "This research and related results were made possible with the support of the NOMIS Foundation. This research was supported by the Scientific Service Units of IST Austria through resources provided by the MIBA Machine Shop and the nanofabrication facility, the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement #844511 and the Grant Agreement #862046. ICN2 acknowledge funding from Generalitat de Catalunya 2017 SGR 327. ICN2 is supported by the Severo Ochoa\r\nprogram from Spanish MINECO (Grant No. SEV2017-0706) and is funded by the CERCA Programme / Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Aut`onoma de Barcelona Materials Science PhD program. The HAADF-STEM microscopy was conducted in the Laboratorio de Microscopias Avanzadas at Instituto de Nanociencia de Aragon-Universidad de Zaragoza. Authors acknowledge the LMA-INA for offering access to their instruments and expertise. We acknowledge support from CSIC Research Platform on Quantum Technologies PTI-001. This project has received funding from\r\nthe European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. M.B. acknowledges support from SUR Generalitat de Catalunya and the EU Social Fund; project ref. 2020 FI 00103. GS and MV acknowledge support through a projectruimte grant associated with the Netherlands Organization of Scientific Research (NWO)." article_number: '2012.00322' article_processing_charge: No author: - first_name: Kushagra full_name: Aggarwal, Kushagra id: b22ab905-3539-11eb-84c3-fc159dcd79cb last_name: Aggarwal orcid: 0000-0001-9985-9293 - first_name: Andrea C full_name: Hofmann, Andrea C id: 340F461A-F248-11E8-B48F-1D18A9856A87 last_name: Hofmann - first_name: Daniel full_name: Jirovec, Daniel id: 4C473F58-F248-11E8-B48F-1D18A9856A87 last_name: Jirovec orcid: 0000-0002-7197-4801 - first_name: Ivan full_name: Prieto Gonzalez, Ivan id: 2A307FE2-F248-11E8-B48F-1D18A9856A87 last_name: Prieto Gonzalez orcid: 0000-0002-7370-5357 - first_name: Amir full_name: Sammak, Amir last_name: Sammak - first_name: Marc full_name: Botifoll, Marc last_name: Botifoll - first_name: Sara full_name: Marti-Sanchez, Sara last_name: Marti-Sanchez - first_name: Menno full_name: Veldhorst, Menno last_name: Veldhorst - first_name: Jordi full_name: Arbiol, Jordi last_name: Arbiol - first_name: Giordano full_name: Scappucci, Giordano last_name: Scappucci - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Aggarwal K, Hofmann AC, Jirovec D, et al. Enhancement of proximity induced superconductivity in planar Germanium. arXiv. apa: Aggarwal, K., Hofmann, A. C., Jirovec, D., Prieto Gonzalez, I., Sammak, A., Botifoll, M., … Katsaros, G. (n.d.). Enhancement of proximity induced superconductivity in planar Germanium. arXiv. chicago: Aggarwal, Kushagra, Andrea C Hofmann, Daniel Jirovec, Ivan Prieto Gonzalez, Amir Sammak, Marc Botifoll, Sara Marti-Sanchez, et al. “Enhancement of Proximity Induced Superconductivity in Planar Germanium.” ArXiv, n.d. ieee: K. Aggarwal et al., “Enhancement of proximity induced superconductivity in planar Germanium,” arXiv. . ista: Aggarwal K, Hofmann AC, Jirovec D, Prieto Gonzalez I, Sammak A, Botifoll M, Marti-Sanchez S, Veldhorst M, Arbiol J, Scappucci G, Katsaros G. Enhancement of proximity induced superconductivity in planar Germanium. arXiv, 2012.00322. mla: Aggarwal, Kushagra, et al. “Enhancement of Proximity Induced Superconductivity in Planar Germanium.” ArXiv, 2012.00322. short: K. Aggarwal, A.C. Hofmann, D. Jirovec, I. Prieto Gonzalez, A. Sammak, M. Botifoll, S. Marti-Sanchez, M. Veldhorst, J. Arbiol, G. Scappucci, G. Katsaros, ArXiv (n.d.). date_created: 2020-12-02T10:42:53Z date_published: 2020-12-02T00:00:00Z date_updated: 2024-03-28T23:30:27Z day: '02' ddc: - '530' department: - _id: GeKa ec_funded: 1 external_id: arxiv: - '2012.00322' file: - access_level: open_access checksum: 22a612e206232fa94b138b2c2f957582 content_type: application/pdf creator: gkatsaro date_created: 2020-12-02T10:42:31Z date_updated: 2020-12-02T10:42:31Z file_id: '8832' file_name: Superconducting_2D_Ge.pdf file_size: 1697939 relation: main_file file_date_updated: 2020-12-02T10:42:31Z has_accepted_license: '1' language: - iso: eng month: '12' oa: 1 oa_version: Submitted Version project: - _id: 262116AA-B435-11E9-9278-68D0E5697425 name: Hybrid Semiconductor - Superconductor Quantum Devices - _id: 26A151DA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '844511' name: Majorana bound states in Ge/SiGe heterostructures - _id: 237E5020-32DE-11EA-91FC-C7463DDC885E call_identifier: H2020 grant_number: '862046' name: TOPOLOGICALLY PROTECTED AND SCALABLE QUANTUM BITS publication: arXiv publication_status: submitted related_material: record: - id: '10559' relation: later_version status: public - id: '8834' relation: research_data status: public - id: '10058' relation: dissertation_contains status: public status: public title: Enhancement of proximity induced superconductivity in planar Germanium type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2020' ... --- _id: '10065' abstract: - lang: eng text: We study double quantum dots in a Ge/SiGe heterostructure and test their maturity towards singlet-triplet ($S-T_0$) qubits. We demonstrate a large range of tunability, from two single quantum dots to a double quantum dot. We measure Pauli spin blockade and study the anisotropy of the $g$-factor. We use an adjacent quantum dot for sensing charge transitions in the double quantum dot at interest. In conclusion, Ge/SiGe possesses all ingredients necessary for building a singlet-triplet qubit. acknowledged_ssus: - _id: M-Shop - _id: NanoFab acknowledgement: "We thank Matthias Brauns for helpful discussions and careful proofreading of the manuscript. This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 844511 and from the FWF project P30207. The research was supported by the Scientific Service Units of IST Austria through resources provided by the MIBA machine shop and the nanofabrication\r\nfacility." article_number: '1910.05841' article_processing_charge: No author: - first_name: Andrea C full_name: Hofmann, Andrea C id: 340F461A-F248-11E8-B48F-1D18A9856A87 last_name: Hofmann - first_name: Daniel full_name: Jirovec, Daniel id: 4C473F58-F248-11E8-B48F-1D18A9856A87 last_name: Jirovec orcid: 0000-0002-7197-4801 - first_name: Maxim full_name: Borovkov, Maxim last_name: Borovkov - first_name: Ivan full_name: Prieto Gonzalez, Ivan id: 2A307FE2-F248-11E8-B48F-1D18A9856A87 last_name: Prieto Gonzalez orcid: 0000-0002-7370-5357 - first_name: Andrea full_name: Ballabio, Andrea last_name: Ballabio - first_name: Jacopo full_name: Frigerio, Jacopo last_name: Frigerio - 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: Hofmann AC, Jirovec D, Borovkov M, et al. Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits. arXiv. doi:10.48550/arXiv.1910.05841 apa: Hofmann, A. C., Jirovec, D., Borovkov, M., Prieto Gonzalez, I., Ballabio, A., Frigerio, J., … Katsaros, G. (n.d.). Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits. arXiv. https://doi.org/10.48550/arXiv.1910.05841 chicago: Hofmann, Andrea C, Daniel Jirovec, Maxim Borovkov, Ivan Prieto Gonzalez, Andrea Ballabio, Jacopo Frigerio, Daniel Chrastina, Giovanni Isella, and Georgios Katsaros. “Assessing the Potential of Ge/SiGe Quantum Dots as Hosts for Singlet-Triplet Qubits.” ArXiv, n.d. https://doi.org/10.48550/arXiv.1910.05841. ieee: A. C. Hofmann et al., “Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits,” arXiv. . ista: Hofmann AC, Jirovec D, Borovkov M, Prieto Gonzalez I, Ballabio A, Frigerio J, Chrastina D, Isella G, Katsaros G. Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits. arXiv, 1910.05841. mla: Hofmann, Andrea C., et al. “Assessing the Potential of Ge/SiGe Quantum Dots as Hosts for Singlet-Triplet Qubits.” ArXiv, 1910.05841, doi:10.48550/arXiv.1910.05841. short: A.C. Hofmann, D. Jirovec, M. Borovkov, I. Prieto Gonzalez, A. Ballabio, J. Frigerio, D. Chrastina, G. Isella, G. Katsaros, ArXiv (n.d.). date_created: 2021-10-01T12:14:51Z date_published: 2019-10-13T00:00:00Z date_updated: 2024-03-28T23:30:27Z day: '13' department: - _id: GeKa doi: 10.48550/arXiv.1910.05841 ec_funded: 1 external_id: arxiv: - '1910.05841' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1910.05841 month: '10' oa: 1 oa_version: Preprint project: - _id: 26A151DA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '844511' name: Majorana bound states in Ge/SiGe heterostructures - _id: 2641CE5E-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P30207 name: Hole spin orbit qubits in Ge quantum wells publication: arXiv publication_status: submitted related_material: record: - id: '10058' relation: dissertation_contains status: public status: public title: Assessing the potential of Ge/SiGe quantum dots as hosts for singlet-triplet qubits type: preprint user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2019' ... --- _id: '5816' abstract: - lang: eng text: Solid-state qubit manipulation and read-out fidelities are reaching fault-tolerance, but quantum error correction requires millions of physical qubits and therefore a scalable quantum computer architecture. To solve signal-line bandwidth and fan-out problems, microwave sources required for qubit manipulation might be embedded close to the qubit chip, typically operating at temperatures below 4 K. Here, we perform the first low temperature measurements of a 130 nm BiCMOS based SiGe voltage controlled oscillator at cryogenic temperature. We determined the frequency and output power dependence on temperature and magnetic field up to 5 T and measured the temperature influence on its noise performance. The device maintains its full functionality from 300 K to 4 K. The carrier frequency at 4 K increases by 3% with respect to the carrier frequency at 300 K, and the output power at 4 K increases by 10 dB relative to the output power at 300 K. The frequency tuning range of approximately 20% remains unchanged between 300 K and 4 K. In an in-plane magnetic field of 5 T, the carrier frequency shifts by only 0.02% compared to the frequency at zero magnetic field. article_number: '114701' article_processing_charge: No author: - first_name: Arne full_name: Hollmann, Arne last_name: Hollmann - first_name: Daniel full_name: Jirovec, Daniel id: 4C473F58-F248-11E8-B48F-1D18A9856A87 last_name: Jirovec orcid: 0000-0002-7197-4801 - first_name: Maciej full_name: Kucharski, Maciej last_name: Kucharski - first_name: Dietmar full_name: Kissinger, Dietmar last_name: Kissinger - first_name: Gunter full_name: Fischer, Gunter last_name: Fischer - first_name: Lars R. full_name: Schreiber, Lars R. last_name: Schreiber citation: ama: Hollmann A, Jirovec D, Kucharski M, Kissinger D, Fischer G, Schreiber LR. 30 GHz-voltage controlled oscillator operating at 4 K. Review of Scientific Instruments. 2018;89(11). doi:10.1063/1.5038258 apa: Hollmann, A., Jirovec, D., Kucharski, M., Kissinger, D., Fischer, G., & Schreiber, L. R. (2018). 30 GHz-voltage controlled oscillator operating at 4 K. Review of Scientific Instruments. AIP Publishing. https://doi.org/10.1063/1.5038258 chicago: Hollmann, Arne, Daniel Jirovec, Maciej Kucharski, Dietmar Kissinger, Gunter Fischer, and Lars R. Schreiber. “30 GHz-Voltage Controlled Oscillator Operating at 4 K.” Review of Scientific Instruments. AIP Publishing, 2018. https://doi.org/10.1063/1.5038258. ieee: A. Hollmann, D. Jirovec, M. Kucharski, D. Kissinger, G. Fischer, and L. R. Schreiber, “30 GHz-voltage controlled oscillator operating at 4 K,” Review of Scientific Instruments, vol. 89, no. 11. AIP Publishing, 2018. ista: Hollmann A, Jirovec D, Kucharski M, Kissinger D, Fischer G, Schreiber LR. 2018. 30 GHz-voltage controlled oscillator operating at 4 K. Review of Scientific Instruments. 89(11), 114701. mla: Hollmann, Arne, et al. “30 GHz-Voltage Controlled Oscillator Operating at 4 K.” Review of Scientific Instruments, vol. 89, no. 11, 114701, AIP Publishing, 2018, doi:10.1063/1.5038258. short: A. Hollmann, D. Jirovec, M. Kucharski, D. Kissinger, G. Fischer, L.R. Schreiber, Review of Scientific Instruments 89 (2018). date_created: 2019-01-10T14:22:23Z date_published: 2018-11-01T00:00:00Z date_updated: 2024-03-28T23:30:27Z day: '01' department: - _id: GeKa doi: 10.1063/1.5038258 external_id: arxiv: - '1804.09522' isi: - '000451735700054' intvolume: ' 89' isi: 1 issue: '11' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1804.09522 month: '11' oa: 1 oa_version: Preprint publication: Review of Scientific Instruments publication_identifier: issn: - '00346748' publication_status: published publisher: AIP Publishing quality_controlled: '1' related_material: record: - id: '10058' relation: dissertation_contains status: public scopus_import: '1' status: public title: 30 GHz-voltage controlled oscillator operating at 4 K type: journal_article user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 89 year: '2018' ...