--- _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: '9464' abstract: - lang: eng text: We firstly introduce the self-assembled growth of highly uniform Ge quantum wires with controllable position, distance and length on patterned Si (001) substrates. We then present the electrically tunable strong spin-orbit coupling, the first Ge hole spin qubit and ultrafast operation of hole spin qubit in the Ge/Si quantum wires. acknowledgement: This work was supported by the National Key R&D Program of China (Grant No. 2016YFA0301700) and the ERC Starting Grant no. 335497. article_number: '9420817' article_processing_charge: No author: - first_name: Fei full_name: Gao, Fei last_name: Gao - first_name: Jie Yin full_name: Zhang, Jie Yin last_name: Zhang - first_name: Jian Huan full_name: Wang, Jian Huan last_name: Wang - first_name: Ming full_name: Ming, Ming last_name: Ming - first_name: Tina full_name: Wang, Tina last_name: Wang - first_name: Jian Jun full_name: Zhang, Jian Jun last_name: Zhang - first_name: Hannes full_name: Watzinger, Hannes id: 35DF8E50-F248-11E8-B48F-1D18A9856A87 last_name: Watzinger - first_name: Josip full_name: Kukucka, Josip id: 3F5D8856-F248-11E8-B48F-1D18A9856A87 last_name: Kukucka - first_name: Lada full_name: Vukušić, Lada id: 31E9F056-F248-11E8-B48F-1D18A9856A87 last_name: Vukušić orcid: 0000-0003-2424-8636 - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X - first_name: Ke full_name: Wang, Ke last_name: Wang - first_name: Gang full_name: Xu, Gang last_name: Xu - first_name: Hai Ou full_name: Li, Hai Ou last_name: Li - first_name: Guo Ping full_name: Guo, Guo Ping last_name: Guo citation: ama: 'Gao F, Zhang JY, Wang JH, et al. Ge/Si quantum wires for quantum computing. In: 2021 5th IEEE Electron Devices Technology and Manufacturing Conference, EDTM 2021. IEEE; 2021. doi:10.1109/EDTM50988.2021.9420817' apa: 'Gao, F., Zhang, J. Y., Wang, J. H., Ming, M., Wang, T., Zhang, J. J., … Guo, G. P. (2021). Ge/Si quantum wires for quantum computing. In 2021 5th IEEE Electron Devices Technology and Manufacturing Conference, EDTM 2021. Virtual, Online: IEEE. https://doi.org/10.1109/EDTM50988.2021.9420817' chicago: Gao, Fei, Jie Yin Zhang, Jian Huan Wang, Ming Ming, Tina Wang, Jian Jun Zhang, Hannes Watzinger, et al. “Ge/Si Quantum Wires for Quantum Computing.” In 2021 5th IEEE Electron Devices Technology and Manufacturing Conference, EDTM 2021. IEEE, 2021. https://doi.org/10.1109/EDTM50988.2021.9420817. ieee: F. Gao et al., “Ge/Si quantum wires for quantum computing,” in 2021 5th IEEE Electron Devices Technology and Manufacturing Conference, EDTM 2021, Virtual, Online, 2021. ista: 'Gao F, Zhang JY, Wang JH, Ming M, Wang T, Zhang JJ, Watzinger H, Kukucka J, Vukušić L, Katsaros G, Wang K, Xu G, Li HO, Guo GP. 2021. Ge/Si quantum wires for quantum computing. 2021 5th IEEE Electron Devices Technology and Manufacturing Conference, EDTM 2021. EDTM: IEEE Electron Devices Technology and Manufacturing Conference, 9420817.' mla: Gao, Fei, et al. “Ge/Si Quantum Wires for Quantum Computing.” 2021 5th IEEE Electron Devices Technology and Manufacturing Conference, EDTM 2021, 9420817, IEEE, 2021, doi:10.1109/EDTM50988.2021.9420817. short: F. Gao, J.Y. Zhang, J.H. Wang, M. Ming, T. Wang, J.J. Zhang, H. Watzinger, J. Kukucka, L. Vukušić, G. Katsaros, K. Wang, G. Xu, H.O. Li, G.P. Guo, in:, 2021 5th IEEE Electron Devices Technology and Manufacturing Conference, EDTM 2021, IEEE, 2021. conference: end_date: 2021-04-11 location: Virtual, Online name: 'EDTM: IEEE Electron Devices Technology and Manufacturing Conference' start_date: 2021-04-08 date_created: 2021-06-06T22:01:29Z date_published: 2021-04-08T00:00:00Z date_updated: 2023-10-03T12:51:59Z day: '08' department: - _id: GeKa doi: 10.1109/EDTM50988.2021.9420817 ec_funded: 1 external_id: isi: - '000675595800006' isi: 1 language: - iso: eng month: '04' oa_version: None project: - _id: 25517E86-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '335497' name: Towards Spin qubits and Majorana fermions in Germanium selfassembled hut-wires publication: 2021 5th IEEE Electron Devices Technology and Manufacturing Conference, EDTM 2021 publication_identifier: isbn: - '9781728181769' publication_status: published publisher: IEEE quality_controlled: '1' scopus_import: '1' status: public title: Ge/Si quantum wires for quantum computing type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 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: '7996' abstract: - lang: eng text: "Quantum computation enables the execution of algorithms that have exponential complexity. This might open the path towards the synthesis of new materials or medical drugs, optimization of transport or financial strategies etc., intractable on even the fastest classical computers. A quantum computer consists of interconnected two level quantum systems, called qubits, that satisfy DiVincezo’s criteria. Worldwide, there are ongoing efforts to find the qubit architecture which will unite quantum error correction compatible single and two qubit fidelities, long distance qubit to qubit coupling and \r\n calability. Superconducting qubits have gone the furthest in this race, demonstrating an algorithm running on 53 coupled qubits, but still the fidelities are not even close to those required for realizing a single logical qubit. emiconductor qubits offer extremely good characteristics, but they are currently investigated across different platforms. Uniting those good characteristics into a single platform might be a big step towards the quantum computer realization.\r\nHere we describe the implementation of a hole spin qubit hosted in a Ge hut wire double quantum dot. The high and tunable spin-orbit coupling together with a heavy hole state character is expected to allow fast spin manipulation and long coherence times. Furthermore large lever arms, for hut wire devices, should allow good coupling to superconducting resonators enabling efficient long distance spin to spin coupling and a sensitive gate reflectometry spin readout. The developed cryogenic setup (printed circuit board sample holders, filtering, high-frequency wiring) enabled us to perform low temperature spin dynamics experiments. Indeed, we measured the fastest single spin qubit Rabi frequencies reported so far, reaching 140 MHz, while the dephasing times of 130 ns oppose the long decoherence predictions. In order to further investigate this, a double quantum dot gate was connected directly to a lumped element\r\nresonator which enabled gate reflectometry readout. The vanishing inter-dot transition signal, for increasing external magnetic field, revealed the spin nature of the measured quantity." alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Josip full_name: Kukucka, Josip id: 3F5D8856-F248-11E8-B48F-1D18A9856A87 last_name: Kukucka citation: ama: Kukucka J. Implementation of a hole spin qubit in Ge hut wires and dispersive spin sensing. 2020. doi:10.15479/AT:ISTA:7996 apa: Kukucka, J. (2020). Implementation of a hole spin qubit in Ge hut wires and dispersive spin sensing. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:7996 chicago: Kukucka, Josip. “Implementation of a Hole Spin Qubit in Ge Hut Wires and Dispersive Spin Sensing.” Institute of Science and Technology Austria, 2020. https://doi.org/10.15479/AT:ISTA:7996. ieee: J. Kukucka, “Implementation of a hole spin qubit in Ge hut wires and dispersive spin sensing,” Institute of Science and Technology Austria, 2020. ista: Kukucka J. 2020. Implementation of a hole spin qubit in Ge hut wires and dispersive spin sensing. Institute of Science and Technology Austria. mla: Kukucka, Josip. Implementation of a Hole Spin Qubit in Ge Hut Wires and Dispersive Spin Sensing. Institute of Science and Technology Austria, 2020, doi:10.15479/AT:ISTA:7996. short: J. Kukucka, Implementation of a Hole Spin Qubit in Ge Hut Wires and Dispersive Spin Sensing, Institute of Science and Technology Austria, 2020. date_created: 2020-06-22T09:22:23Z date_published: 2020-06-22T00:00:00Z date_updated: 2023-09-26T15:50:22Z day: '22' ddc: - '530' degree_awarded: PhD department: - _id: GeKa doi: 10.15479/AT:ISTA:7996 file: - access_level: closed checksum: 467e52feb3e361ce8cf5fe8d5c254ece content_type: application/x-zip-compressed creator: dernst date_created: 2020-06-22T09:22:04Z date_updated: 2020-07-14T12:48:07Z file_id: '7997' file_name: JK_thesis_latex_source_files.zip file_size: 392794743 relation: main_file - access_level: open_access checksum: 1de716bf110dbd77d383e479232bf496 content_type: application/pdf creator: dernst date_created: 2020-06-22T09:21:29Z date_updated: 2020-07-14T12:48:07Z file_id: '7998' file_name: PhD_thesis_JK_pdfa.pdf file_size: 28453247 relation: main_file file_date_updated: 2020-07-14T12:48:07Z has_accepted_license: '1' language: - iso: eng month: '06' oa: 1 oa_version: Published Version page: '178' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '1328' relation: part_of_dissertation status: public - id: '7541' relation: part_of_dissertation status: public - id: '77' relation: part_of_dissertation status: public - id: '23' relation: part_of_dissertation status: public - id: '840' 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: Implementation of a hole spin qubit in Ge hut wires and dispersive spin sensing type: dissertation user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2020' ... --- _id: '7541' abstract: - lang: eng text: Semiconductor nanowires have been playing a crucial role in the development of nanoscale devices for the realization of spin qubits, Majorana fermions, single photon emitters, nanoprocessors, etc. The monolithic growth of site‐controlled nanowires is a prerequisite toward the next generation of devices that will require addressability and scalability. Here, combining top‐down nanofabrication and bottom‐up self‐assembly, the growth of Ge wires on prepatterned Si (001) substrates with controllable position, distance, length, and structure is reported. This is achieved by a novel growth process that uses a SiGe strain‐relaxation template and can be potentially generalized to other material combinations. Transport measurements show an electrically tunable spin–orbit coupling, with a spin–orbit length similar to that of III–V materials. Also, charge sensing between quantum dots in closely spaced wires is observed, which underlines their potential for the realization of advanced quantum devices. The reported results open a path toward scalable qubit devices using nanowires on silicon. acknowledged_ssus: - _id: NanoFab - _id: M-Shop acknowledgement: 'This work was supported by the National Key R&D Program of China (Grant Nos. 2016YFA0301701 and 2016YFA0300600), the NSFC (Grant Nos. 11574356, 11434010, and 11404252), the Strategic Priority Research Program of CAS (Grant No. XDB30000000), the ERC Starting Grant No. 335497, the FWF P32235 project, and the European Union''s Horizon 2020 research and innovation program under Grant Agreement #862046. This research was supported by the Scientific Service Units of IST Austria through resources provided by the MIBA Machine Shop and the nanofabrication facility. F.L. thanks support from DOE (Grant No. DE‐FG02‐04ER46148). H.H. thanks the Startup Funding from Xi''an Jiaotong University.' article_number: '1906523' article_processing_charge: Yes (via OA deal) article_type: original author: - first_name: Fei full_name: Gao, Fei last_name: Gao - first_name: Jian-Huan full_name: Wang, Jian-Huan last_name: Wang - first_name: Hannes full_name: Watzinger, Hannes id: 35DF8E50-F248-11E8-B48F-1D18A9856A87 last_name: Watzinger - first_name: Hao full_name: Hu, Hao last_name: Hu - first_name: Marko J. full_name: Rančić, Marko J. last_name: Rančić - first_name: Jie-Yin full_name: Zhang, Jie-Yin last_name: Zhang - first_name: Ting full_name: Wang, Ting last_name: Wang - first_name: Yuan full_name: Yao, Yuan last_name: Yao - first_name: Gui-Lei full_name: Wang, Gui-Lei last_name: Wang - first_name: Josip full_name: Kukucka, Josip id: 3F5D8856-F248-11E8-B48F-1D18A9856A87 last_name: Kukucka - first_name: Lada full_name: Vukušić, Lada id: 31E9F056-F248-11E8-B48F-1D18A9856A87 last_name: Vukušić orcid: 0000-0003-2424-8636 - first_name: Christoph full_name: Kloeffel, Christoph last_name: Kloeffel - first_name: Daniel full_name: Loss, Daniel last_name: Loss - first_name: Feng full_name: Liu, Feng last_name: Liu - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X - first_name: Jian-Jun full_name: Zhang, Jian-Jun last_name: Zhang citation: ama: Gao F, Wang J-H, Watzinger H, et al. Site-controlled uniform Ge/Si hut wires with electrically tunable spin-orbit coupling. Advanced Materials. 2020;32(16). doi:10.1002/adma.201906523 apa: Gao, F., Wang, J.-H., Watzinger, H., Hu, H., Rančić, M. J., Zhang, J.-Y., … Zhang, J.-J. (2020). Site-controlled uniform Ge/Si hut wires with electrically tunable spin-orbit coupling. Advanced Materials. Wiley. https://doi.org/10.1002/adma.201906523 chicago: Gao, Fei, Jian-Huan Wang, Hannes Watzinger, Hao Hu, Marko J. Rančić, Jie-Yin Zhang, Ting Wang, et al. “Site-Controlled Uniform Ge/Si Hut Wires with Electrically Tunable Spin-Orbit Coupling.” Advanced Materials. Wiley, 2020. https://doi.org/10.1002/adma.201906523. ieee: F. Gao et al., “Site-controlled uniform Ge/Si hut wires with electrically tunable spin-orbit coupling,” Advanced Materials, vol. 32, no. 16. Wiley, 2020. ista: Gao F, Wang J-H, Watzinger H, Hu H, Rančić MJ, Zhang J-Y, Wang T, Yao Y, Wang G-L, Kukucka J, Vukušić L, Kloeffel C, Loss D, Liu F, Katsaros G, Zhang J-J. 2020. Site-controlled uniform Ge/Si hut wires with electrically tunable spin-orbit coupling. Advanced Materials. 32(16), 1906523. mla: Gao, Fei, et al. “Site-Controlled Uniform Ge/Si Hut Wires with Electrically Tunable Spin-Orbit Coupling.” Advanced Materials, vol. 32, no. 16, 1906523, Wiley, 2020, doi:10.1002/adma.201906523. short: F. Gao, J.-H. Wang, H. Watzinger, H. Hu, M.J. Rančić, J.-Y. Zhang, T. Wang, Y. Yao, G.-L. Wang, J. Kukucka, L. Vukušić, C. Kloeffel, D. Loss, F. Liu, G. Katsaros, J.-J. Zhang, Advanced Materials 32 (2020). date_created: 2020-02-28T09:47:00Z date_published: 2020-04-23T00:00:00Z date_updated: 2024-02-21T12:42:12Z day: '23' ddc: - '530' department: - _id: GeKa doi: 10.1002/adma.201906523 ec_funded: 1 external_id: isi: - '000516660900001' file: - access_level: open_access checksum: c622737dc295972065782558337124a2 content_type: application/pdf creator: dernst date_created: 2020-11-20T10:11:35Z date_updated: 2020-11-20T10:11:35Z file_id: '8782' file_name: 2020_AdvancedMaterials_Gao.pdf file_size: 5242880 relation: main_file success: 1 file_date_updated: 2020-11-20T10:11:35Z has_accepted_license: '1' intvolume: ' 32' isi: 1 issue: '16' language: - iso: eng month: '04' oa: 1 oa_version: Published Version project: - _id: 25517E86-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '335497' name: Towards Spin qubits and Majorana fermions in Germanium selfassembled hut-wires - _id: 237B3DA4-32DE-11EA-91FC-C7463DDC885E call_identifier: FWF grant_number: P32235 name: Towards scalable hut wire quantum devices - _id: 237E5020-32DE-11EA-91FC-C7463DDC885E call_identifier: H2020 grant_number: '862046' name: TOPOLOGICALLY PROTECTED AND SCALABLE QUANTUM BITS publication: Advanced Materials publication_identifier: issn: - 0935-9648 publication_status: published publisher: Wiley quality_controlled: '1' related_material: record: - id: '7996' relation: dissertation_contains status: public - id: '9222' relation: research_data status: public scopus_import: '1' status: public title: Site-controlled uniform Ge/Si hut wires with electrically tunable spin-orbit coupling 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: 32 year: '2020' ... --- _id: '8203' abstract: - lang: eng text: Using inelastic cotunneling spectroscopy we observe a zero field splitting within the spin triplet manifold of Ge hut wire quantum dots. The states with spin ±1 in the confinement direction are energetically favored by up to 55 μeV compared to the spin 0 triplet state because of the strong spin–orbit coupling. The reported effect should be observable in a broad class of strongly confined hole quantum-dot systems and might need to be considered when operating hole spin qubits. acknowledged_ssus: - _id: NanoFab - _id: M-Shop acknowledgement: "We acknowledge G. Burkard, V. N. Golovach, C. Kloeffel, D.Loss, P. Rabl, and M. Rancič ́ for helpful discussions. We\r\nfurther acknowledge T. Adletzberger, J. Aguilera, T. Asenov, S. Bagiante, T. Menner, L. Shafeek, P. Taus, P. Traunmüller, and D. Waldhausl for their invaluable assistance. This research was supported by the Scientific Service Units of IST Austria through resources provided by the MIBA Machine Shop and the nanofabrication facility, by the FWF-P 32235 project, by the National Key R&D Program of China (2016YFA0301701, 2016YFA0300600), and by the European Union’s Horizon 2020 research and innovation program under grant agreement no. 862046. All data of this publication are available at 10.15479/AT:ISTA:7689." article_processing_charge: Yes (via OA deal) article_type: original author: - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X - first_name: Josip full_name: Kukucka, Josip id: 3F5D8856-F248-11E8-B48F-1D18A9856A87 last_name: Kukucka - first_name: Lada full_name: Vukušić, Lada id: 31E9F056-F248-11E8-B48F-1D18A9856A87 last_name: Vukušić orcid: 0000-0003-2424-8636 - first_name: Hannes full_name: Watzinger, Hannes id: 35DF8E50-F248-11E8-B48F-1D18A9856A87 last_name: Watzinger - first_name: Fei full_name: Gao, Fei last_name: Gao - first_name: Ting full_name: Wang, Ting last_name: Wang orcid: 0000-0002-4619-9575 - first_name: Jian-Jun full_name: Zhang, Jian-Jun last_name: Zhang - first_name: Karsten full_name: Held, Karsten last_name: Held citation: ama: Katsaros G, Kukucka J, Vukušić L, et al. Zero field splitting of heavy-hole states in quantum dots. Nano Letters. 2020;20(7):5201-5206. doi:10.1021/acs.nanolett.0c01466 apa: Katsaros, G., Kukucka, J., Vukušić, L., Watzinger, H., Gao, F., Wang, T., … Held, K. (2020). Zero field splitting of heavy-hole states in quantum dots. Nano Letters. American Chemical Society. https://doi.org/10.1021/acs.nanolett.0c01466 chicago: Katsaros, Georgios, Josip Kukucka, Lada Vukušić, Hannes Watzinger, Fei Gao, Ting Wang, Jian-Jun Zhang, and Karsten Held. “Zero Field Splitting of Heavy-Hole States in Quantum Dots.” Nano Letters. American Chemical Society, 2020. https://doi.org/10.1021/acs.nanolett.0c01466. ieee: G. Katsaros et al., “Zero field splitting of heavy-hole states in quantum dots,” Nano Letters, vol. 20, no. 7. American Chemical Society, pp. 5201–5206, 2020. ista: Katsaros G, Kukucka J, Vukušić L, Watzinger H, Gao F, Wang T, Zhang J-J, Held K. 2020. Zero field splitting of heavy-hole states in quantum dots. Nano Letters. 20(7), 5201–5206. mla: Katsaros, Georgios, et al. “Zero Field Splitting of Heavy-Hole States in Quantum Dots.” Nano Letters, vol. 20, no. 7, American Chemical Society, 2020, pp. 5201–06, doi:10.1021/acs.nanolett.0c01466. short: G. Katsaros, J. Kukucka, L. Vukušić, H. Watzinger, F. Gao, T. Wang, J.-J. Zhang, K. Held, Nano Letters 20 (2020) 5201–5206. date_created: 2020-08-06T09:25:04Z date_published: 2020-06-01T00:00:00Z date_updated: 2024-02-21T12:44:01Z day: '01' ddc: - '530' department: - _id: GeKa doi: 10.1021/acs.nanolett.0c01466 ec_funded: 1 external_id: isi: - '000548893200066' pmid: - '32479090' file: - access_level: open_access content_type: application/pdf creator: dernst date_created: 2020-08-06T09:35:37Z date_updated: 2020-08-06T09:35:37Z file_id: '8204' file_name: 2020_NanoLetters_Katsaros.pdf file_size: 3308906 relation: main_file success: 1 file_date_updated: 2020-08-06T09:35:37Z has_accepted_license: '1' intvolume: ' 20' isi: 1 issue: '7' language: - iso: eng month: '06' oa: 1 oa_version: Published Version page: 5201-5206 pmid: 1 project: - _id: 237B3DA4-32DE-11EA-91FC-C7463DDC885E call_identifier: FWF grant_number: P32235 name: Towards scalable hut wire quantum devices - _id: 237E5020-32DE-11EA-91FC-C7463DDC885E call_identifier: H2020 grant_number: '862046' name: TOPOLOGICALLY PROTECTED AND SCALABLE QUANTUM BITS publication: Nano Letters publication_identifier: eissn: - 1530-6992 issn: - 1530-6984 publication_status: published publisher: American Chemical Society quality_controlled: '1' related_material: record: - id: '7689' relation: research_data status: public scopus_import: '1' status: public title: Zero field splitting of heavy-hole states in quantum dots 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: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 20 year: '2020' ... --- _id: '77' abstract: - lang: eng text: Holes confined in quantum dots have gained considerable interest in the past few years due to their potential as spin qubits. Here we demonstrate two-axis control of a spin 3/2 qubit in natural Ge. The qubit is formed in a hut wire double quantum dot device. The Pauli spin blockade principle allowed us to demonstrate electric dipole spin resonance by applying a radio frequency electric field to one of the electrodes defining the double quantum dot. Coherent hole spin oscillations with Rabi frequencies reaching 140 MHz are demonstrated and dephasing times of 130 ns are measured. The reported results emphasize the potential of Ge as a platform for fast and electrically tunable hole spin qubit devices. acknowledged_ssus: - _id: M-Shop - _id: NanoFab article_processing_charge: Yes article_type: original author: - first_name: Hannes full_name: Watzinger, Hannes id: 35DF8E50-F248-11E8-B48F-1D18A9856A87 last_name: Watzinger - first_name: Josip full_name: Kukucka, Josip id: 3F5D8856-F248-11E8-B48F-1D18A9856A87 last_name: Kukucka - first_name: Lada full_name: Vukusic, Lada id: 31E9F056-F248-11E8-B48F-1D18A9856A87 last_name: Vukusic orcid: 0000-0003-2424-8636 - first_name: Fei full_name: Gao, Fei last_name: Gao - first_name: Ting full_name: Wang, Ting last_name: Wang - first_name: Friedrich full_name: Schäffler, Friedrich last_name: Schäffler - first_name: Jian full_name: Zhang, Jian last_name: Zhang - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Watzinger H, Kukucka J, Vukušić L, et al. A germanium hole spin qubit. Nature Communications. 2018;9(3902). doi:10.1038/s41467-018-06418-4 apa: Watzinger, H., Kukucka, J., Vukušić, L., Gao, F., Wang, T., Schäffler, F., … Katsaros, G. (2018). A germanium hole spin qubit. Nature Communications. Nature Publishing Group. https://doi.org/10.1038/s41467-018-06418-4 chicago: Watzinger, Hannes, Josip Kukucka, Lada Vukušić, Fei Gao, Ting Wang, Friedrich Schäffler, Jian Zhang, and Georgios Katsaros. “A Germanium Hole Spin Qubit.” Nature Communications. Nature Publishing Group, 2018. https://doi.org/10.1038/s41467-018-06418-4. ieee: H. Watzinger et al., “A germanium hole spin qubit,” Nature Communications, vol. 9, no. 3902. Nature Publishing Group, 2018. ista: Watzinger H, Kukucka J, Vukušić L, Gao F, Wang T, Schäffler F, Zhang J, Katsaros G. 2018. A germanium hole spin qubit. Nature Communications. 9(3902). mla: Watzinger, Hannes, et al. “A Germanium Hole Spin Qubit.” Nature Communications, vol. 9, no. 3902, Nature Publishing Group, 2018, doi:10.1038/s41467-018-06418-4. short: H. Watzinger, J. Kukucka, L. Vukušić, F. Gao, T. Wang, F. Schäffler, J. Zhang, G. Katsaros, Nature Communications 9 (2018). date_created: 2018-12-11T11:44:30Z date_published: 2018-09-25T00:00:00Z date_updated: 2023-09-08T11:44:02Z day: '25' ddc: - '530' department: - _id: GeKa doi: 10.1038/s41467-018-06418-4 ec_funded: 1 external_id: isi: - '000445560800010' file: - access_level: open_access checksum: e7148c10a64497e279c4de570b6cc544 content_type: application/pdf creator: dernst date_created: 2018-12-17T10:28:30Z date_updated: 2020-07-14T12:48:02Z file_id: '5687' file_name: 2018_NatureComm_Watzinger.pdf file_size: 1063469 relation: main_file file_date_updated: 2020-07-14T12:48:02Z has_accepted_license: '1' intvolume: ' 9' isi: 1 issue: '3902 ' language: - iso: eng month: '09' oa: 1 oa_version: Published Version project: - _id: 25517E86-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '335497' name: Towards Spin qubits and Majorana fermions in Germanium selfassembled hut-wires - _id: 2552F888-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: Y00715 name: Loch Spin-Qubits und Majorana-Fermionen in Germanium publication: Nature Communications publication_status: published publisher: Nature Publishing Group quality_controlled: '1' related_material: record: - id: '7977' relation: popular_science - id: '7996' relation: dissertation_contains status: public scopus_import: '1' status: public title: A germanium hole spin qubit 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: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 9 year: '2018' ... --- _id: '23' abstract: - lang: eng text: The strong atomistic spin–orbit coupling of holes makes single-shot spin readout measurements difficult because it reduces the spin lifetimes. By integrating the charge sensor into a high bandwidth radio frequency reflectometry setup, we were able to demonstrate single-shot readout of a germanium quantum dot hole spin and measure the spin lifetime. Hole spin relaxation times of about 90 μs at 500 mT are reported, with a total readout visibility of about 70%. By analyzing separately the spin-to-charge conversion and charge readout fidelities, we have obtained insight into the processes limiting the visibilities of hole spins. The analyses suggest that high hole visibilities are feasible at realistic experimental conditions, underlying the potential of hole spins for the realization of viable qubit devices. acknowledged_ssus: - _id: M-Shop - _id: NanoFab article_processing_charge: No author: - first_name: Lada full_name: Vukušić, Lada id: 31E9F056-F248-11E8-B48F-1D18A9856A87 last_name: Vukušić orcid: 0000-0003-2424-8636 - first_name: Josip full_name: Kukucka, Josip id: 3F5D8856-F248-11E8-B48F-1D18A9856A87 last_name: Kukucka - first_name: Hannes full_name: Watzinger, Hannes id: 35DF8E50-F248-11E8-B48F-1D18A9856A87 last_name: Watzinger - first_name: Joshua M full_name: Milem, Joshua M id: 4CDE0A96-F248-11E8-B48F-1D18A9856A87 last_name: Milem - first_name: Friedrich full_name: Schäffler, Friedrich last_name: Schäffler - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Vukušić L, Kukucka J, Watzinger H, Milem JM, Schäffler F, Katsaros G. Single-shot readout of hole spins in Ge. Nano Letters. 2018;18(11):7141-7145. doi:10.1021/acs.nanolett.8b03217 apa: Vukušić, L., Kukucka, J., Watzinger, H., Milem, J. M., Schäffler, F., & Katsaros, G. (2018). Single-shot readout of hole spins in Ge. Nano Letters. American Chemical Society. https://doi.org/10.1021/acs.nanolett.8b03217 chicago: Vukušić, Lada, Josip Kukucka, Hannes Watzinger, Joshua M Milem, Friedrich Schäffler, and Georgios Katsaros. “Single-Shot Readout of Hole Spins in Ge.” Nano Letters. American Chemical Society, 2018. https://doi.org/10.1021/acs.nanolett.8b03217. ieee: L. Vukušić, J. Kukucka, H. Watzinger, J. M. Milem, F. Schäffler, and G. Katsaros, “Single-shot readout of hole spins in Ge,” Nano Letters, vol. 18, no. 11. American Chemical Society, pp. 7141–7145, 2018. ista: Vukušić L, Kukucka J, Watzinger H, Milem JM, Schäffler F, Katsaros G. 2018. Single-shot readout of hole spins in Ge. Nano Letters. 18(11), 7141–7145. mla: Vukušić, Lada, et al. “Single-Shot Readout of Hole Spins in Ge.” Nano Letters, vol. 18, no. 11, American Chemical Society, 2018, pp. 7141–45, doi:10.1021/acs.nanolett.8b03217. short: L. Vukušić, J. Kukucka, H. Watzinger, J.M. Milem, F. Schäffler, G. Katsaros, Nano Letters 18 (2018) 7141–7145. date_created: 2018-12-11T11:44:13Z date_published: 2018-10-25T00:00:00Z date_updated: 2023-09-18T09:30:37Z day: '25' ddc: - '530' department: - _id: GeKa doi: 10.1021/acs.nanolett.8b03217 ec_funded: 1 external_id: isi: - '000451102100064' pmid: - '30359041' file: - access_level: open_access checksum: 3e6034a94c6b5335e939145d88bdb371 content_type: application/pdf creator: system date_created: 2018-12-12T10:16:08Z date_updated: 2020-07-14T12:45:37Z file_id: '5194' file_name: IST-2018-1065-v1+1_ACS_nanoletters_8b03217.pdf file_size: 1361441 relation: main_file file_date_updated: 2020-07-14T12:45:37Z has_accepted_license: '1' intvolume: ' 18' isi: 1 issue: '11' language: - iso: eng month: '10' oa: 1 oa_version: Published Version page: 7141 - 7145 pmid: 1 project: - _id: 25517E86-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '335497' name: Towards Spin qubits and Majorana fermions in Germanium selfassembled hut-wires publication: Nano Letters publication_identifier: issn: - '15306984' publication_status: published publisher: American Chemical Society publist_id: '8032' pubrep_id: '1065' quality_controlled: '1' related_material: record: - id: '7977' relation: popular_science - id: '69' relation: dissertation_contains status: public - id: '7996' relation: dissertation_contains status: public scopus_import: '1' status: public title: Single-shot readout of hole spins in 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: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 18 year: '2018' ... --- _id: '840' abstract: - lang: eng text: Heavy holes confined in quantum dots are predicted to be promising candidates for the realization of spin qubits with long coherence times. Here we focus on such heavy-hole states confined in germanium hut wires. By tuning the growth density of the latter we can realize a T-like structure between two neighboring wires. Such a structure allows the realization of a charge sensor, which is electrostatically and tunnel coupled to a quantum dot, with charge-transfer signals as high as 0.3 e. By integrating the T-like structure into a radiofrequency reflectometry setup, single-shot measurements allowing the extraction of hole tunneling times are performed. The extracted tunneling times of less than 10 μs are attributed to the small effective mass of Ge heavy-hole states and pave the way toward projective spin readout measurements. acknowledged_ssus: - _id: M-Shop article_processing_charge: No author: - first_name: Lada full_name: Vukusic, Lada id: 31E9F056-F248-11E8-B48F-1D18A9856A87 last_name: Vukusic orcid: 0000-0003-2424-8636 - first_name: Josip full_name: Kukucka, Josip id: 3F5D8856-F248-11E8-B48F-1D18A9856A87 last_name: Kukucka - first_name: Hannes full_name: Watzinger, Hannes id: 35DF8E50-F248-11E8-B48F-1D18A9856A87 last_name: Watzinger - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Vukušić L, Kukucka J, Watzinger H, Katsaros G. Fast hole tunneling times in germanium hut wires probed by single-shot reflectometry. Nano Letters. 2017;17(9):5706-5710. doi:10.1021/acs.nanolett.7b02627 apa: Vukušić, L., Kukucka, J., Watzinger, H., & Katsaros, G. (2017). Fast hole tunneling times in germanium hut wires probed by single-shot reflectometry. Nano Letters. American Chemical Society. https://doi.org/10.1021/acs.nanolett.7b02627 chicago: Vukušić, Lada, Josip Kukucka, Hannes Watzinger, and Georgios Katsaros. “Fast Hole Tunneling Times in Germanium Hut Wires Probed by Single-Shot Reflectometry.” Nano Letters. American Chemical Society, 2017. https://doi.org/10.1021/acs.nanolett.7b02627. ieee: L. Vukušić, J. Kukucka, H. Watzinger, and G. Katsaros, “Fast hole tunneling times in germanium hut wires probed by single-shot reflectometry,” Nano Letters, vol. 17, no. 9. American Chemical Society, pp. 5706–5710, 2017. ista: Vukušić L, Kukucka J, Watzinger H, Katsaros G. 2017. Fast hole tunneling times in germanium hut wires probed by single-shot reflectometry. Nano Letters. 17(9), 5706–5710. mla: Vukušić, Lada, et al. “Fast Hole Tunneling Times in Germanium Hut Wires Probed by Single-Shot Reflectometry.” Nano Letters, vol. 17, no. 9, American Chemical Society, 2017, pp. 5706–10, doi:10.1021/acs.nanolett.7b02627. short: L. Vukušić, J. Kukucka, H. Watzinger, G. Katsaros, Nano Letters 17 (2017) 5706–5710. date_created: 2018-12-11T11:48:47Z date_published: 2017-08-10T00:00:00Z date_updated: 2023-09-26T15:50:22Z day: '10' ddc: - '539' department: - _id: GeKa doi: 10.1021/acs.nanolett.7b02627 ec_funded: 1 external_id: isi: - '000411043500078' file: - access_level: open_access checksum: 761371a0129b2aa442424b9561450ece content_type: application/pdf creator: system date_created: 2018-12-12T10:12:33Z date_updated: 2020-07-14T12:48:13Z file_id: '4951' file_name: IST-2017-865-v1+1_acs.nanolett.7b02627.pdf file_size: 2449546 relation: main_file file_date_updated: 2020-07-14T12:48:13Z has_accepted_license: '1' intvolume: ' 17' isi: 1 issue: '9' language: - iso: eng month: '08' oa: 1 oa_version: Published Version page: 5706 - 5710 project: - _id: 25517E86-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '335497' name: Towards Spin qubits and Majorana fermions in Germanium selfassembled hut-wires publication: Nano Letters publication_identifier: issn: - '15306984' publication_status: published publisher: American Chemical Society publist_id: '6808' pubrep_id: '865' quality_controlled: '1' related_material: record: - id: '7977' relation: popular_science - id: '69' relation: dissertation_contains status: public - id: '7996' relation: dissertation_contains status: public scopus_import: '1' status: public title: Fast hole tunneling times in germanium hut wires probed by single-shot reflectometry 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: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 17 year: '2017' ... --- _id: '1328' abstract: - lang: eng text: Hole spins have gained considerable interest in the past few years due to their potential for fast electrically controlled qubits. Here, we study holes confined in Ge hut wires, a so-far unexplored type of nanostructure. Low-temperature magnetotransport measurements reveal a large anisotropy between the in-plane and out-of-plane g-factors of up to 18. Numerical simulations verify that this large anisotropy originates from a confined wave function of heavy-hole character. A light-hole admixture of less than 1% is estimated for the states of lowest energy, leading to a surprisingly large reduction of the out-of-plane g-factors compared with those for pure heavy holes. Given this tiny light-hole contribution, the spin lifetimes are expected to be very long, even in isotopically nonpurified samples. acknowledgement: 'The work was supported by the EC FP7 ICT project SiSPIN no. 323841, the EC FP7 ICT project PAMS no. 610446, the ERC Starting Grant no. 335497, the FWF-I-1190-N20 project, and the Swiss NSF. We acknowledge F. Schäffler for fruitful discussions related to the hut wire growth and for giving us access to the molecular beam epitaxy system, M. Schatzl for her support in electron beam lithography, and V. Jadris ̌ko for helping us with the COMSOL simulations. Finally, we thank G. Bauer for his continuous support. ' author: - first_name: Hannes full_name: Watzinger, Hannes id: 35DF8E50-F248-11E8-B48F-1D18A9856A87 last_name: Watzinger - first_name: Christoph full_name: Kloeffel, Christoph last_name: Kloeffel - first_name: Lada full_name: Vukusic, Lada id: 31E9F056-F248-11E8-B48F-1D18A9856A87 last_name: Vukusic orcid: 0000-0003-2424-8636 - first_name: Marta full_name: Rossell, Marta last_name: Rossell - first_name: Violetta full_name: Sessi, Violetta last_name: Sessi - first_name: Josip full_name: Kukucka, Josip id: 3F5D8856-F248-11E8-B48F-1D18A9856A87 last_name: Kukucka - first_name: Raimund full_name: Kirchschlager, Raimund last_name: Kirchschlager - first_name: Elisabeth full_name: Lausecker, Elisabeth id: 33662F76-F248-11E8-B48F-1D18A9856A87 last_name: Lausecker - first_name: Alisha full_name: Truhlar, Alisha id: 49CBC780-F248-11E8-B48F-1D18A9856A87 last_name: Truhlar - first_name: Martin full_name: Glaser, Martin last_name: Glaser - first_name: Armando full_name: Rastelli, Armando last_name: Rastelli - first_name: Andreas full_name: Fuhrer, Andreas last_name: Fuhrer - first_name: Daniel full_name: Loss, Daniel last_name: Loss - first_name: Georgios full_name: Katsaros, Georgios id: 38DB5788-F248-11E8-B48F-1D18A9856A87 last_name: Katsaros orcid: 0000-0001-8342-202X citation: ama: Watzinger H, Kloeffel C, Vukušić L, et al. Heavy-hole states in germanium hut wires. Nano Letters. 2016;16(11):6879-6885. doi:10.1021/acs.nanolett.6b02715 apa: Watzinger, H., Kloeffel, C., Vukušić, L., Rossell, M., Sessi, V., Kukucka, J., … Katsaros, G. (2016). Heavy-hole states in germanium hut wires. Nano Letters. American Chemical Society. https://doi.org/10.1021/acs.nanolett.6b02715 chicago: Watzinger, Hannes, Christoph Kloeffel, Lada Vukušić, Marta Rossell, Violetta Sessi, Josip Kukucka, Raimund Kirchschlager, et al. “Heavy-Hole States in Germanium Hut Wires.” Nano Letters. American Chemical Society, 2016. https://doi.org/10.1021/acs.nanolett.6b02715. ieee: H. Watzinger et al., “Heavy-hole states in germanium hut wires,” Nano Letters, vol. 16, no. 11. American Chemical Society, pp. 6879–6885, 2016. ista: Watzinger H, Kloeffel C, Vukušić L, Rossell M, Sessi V, Kukucka J, Kirchschlager R, Lausecker E, Truhlar A, Glaser M, Rastelli A, Fuhrer A, Loss D, Katsaros G. 2016. Heavy-hole states in germanium hut wires. Nano Letters. 16(11), 6879–6885. mla: Watzinger, Hannes, et al. “Heavy-Hole States in Germanium Hut Wires.” Nano Letters, vol. 16, no. 11, American Chemical Society, 2016, pp. 6879–85, doi:10.1021/acs.nanolett.6b02715. short: H. Watzinger, C. Kloeffel, L. Vukušić, M. Rossell, V. Sessi, J. Kukucka, R. Kirchschlager, E. Lausecker, A. Truhlar, M. Glaser, A. Rastelli, A. Fuhrer, D. Loss, G. Katsaros, Nano Letters 16 (2016) 6879–6885. date_created: 2018-12-11T11:51:24Z date_published: 2016-09-22T00:00:00Z date_updated: 2023-09-07T13:15:02Z day: '22' ddc: - '539' department: - _id: GeKa doi: 10.1021/acs.nanolett.6b02715 ec_funded: 1 file: - access_level: open_access checksum: b63feece90d7b620ece49ca632e34ff3 content_type: application/pdf creator: system date_created: 2018-12-12T10:14:04Z date_updated: 2020-07-14T12:44:44Z file_id: '5053' file_name: IST-2016-664-v1+1_acs.nanolett.6b02715.pdf file_size: 535121 relation: main_file file_date_updated: 2020-07-14T12:44:44Z has_accepted_license: '1' intvolume: ' 16' issue: '11' language: - iso: eng month: '09' oa: 1 oa_version: Published Version page: 6879 - 6885 project: - _id: 25517E86-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '335497' name: Towards Spin qubits and Majorana fermions in Germanium selfassembled hut-wires publication: Nano Letters publication_status: published publisher: American Chemical Society publist_id: '5941' pubrep_id: '664' quality_controlled: '1' related_material: record: - id: '7977' relation: popular_science status: for_moderation - id: '7996' relation: dissertation_contains status: public scopus_import: 1 status: public title: Heavy-hole states in germanium hut wires 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: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87 volume: 16 year: '2016' ...