--- _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: '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: '49' abstract: - lang: eng text: Nowadays, quantum computation is receiving more and more attention as an alternative to the classical way of computing. For realizing a quantum computer, different devices are investigated as potential quantum bits. In this thesis, the focus is on Ge hut wires, which turned out to be promising candidates for implementing hole spin quantum bits. The advantages of Ge as a material system are the low hyperfine interaction for holes and the strong spin orbit coupling, as well as the compatibility with the highly developed CMOS processes in industry. In addition, Ge can also be isotopically purified which is expected to boost the spin coherence times. The strong spin orbit interaction for holes in Ge on the one hand enables the full electrical control of the quantum bit and on the other hand should allow short spin manipulation times. Starting with a bare Si wafer, this work covers the entire process reaching from growth over the fabrication and characterization of hut wire devices up to the demonstration of hole spin resonance. From experiments with single quantum dots, a large g-factor anisotropy between the in-plane and the out-of-plane direction was found. A comparison to a theoretical model unveiled the heavy-hole character of the lowest energy states. The second part of the thesis addresses double quantum dot devices, which were realized by adding two gate electrodes to a hut wire. In such devices, Pauli spin blockade was observed, which can serve as a read-out mechanism for spin quantum bits. Applying oscillating electric fields in spin blockade allowed the demonstration of continuous spin rotations and the extraction of a lower bound for the spin dephasing time. Despite the strong spin orbit coupling in Ge, the obtained value for the dephasing time is comparable to what has been recently reported for holes in Si. All in all, the presented results point out the high potential of Ge hut wires as a platform for long-lived, fast and fully electrically tunable hole spin quantum bits. alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Hannes full_name: Watzinger, Hannes id: 35DF8E50-F248-11E8-B48F-1D18A9856A87 last_name: Watzinger citation: ama: Watzinger H. Ge hut wires - from growth to hole spin resonance. 2018. doi:10.15479/AT:ISTA:th_1033 apa: Watzinger, H. (2018). Ge hut wires - from growth to hole spin resonance. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:th_1033 chicago: Watzinger, Hannes. “Ge Hut Wires - from Growth to Hole Spin Resonance.” Institute of Science and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:th_1033. ieee: H. Watzinger, “Ge hut wires - from growth to hole spin resonance,” Institute of Science and Technology Austria, 2018. ista: Watzinger H. 2018. Ge hut wires - from growth to hole spin resonance. Institute of Science and Technology Austria. mla: Watzinger, Hannes. Ge Hut Wires - from Growth to Hole Spin Resonance. Institute of Science and Technology Austria, 2018, doi:10.15479/AT:ISTA:th_1033. short: H. Watzinger, Ge Hut Wires - from Growth to Hole Spin Resonance, Institute of Science and Technology Austria, 2018. date_created: 2018-12-11T11:44:21Z date_published: 2018-07-30T00:00:00Z date_updated: 2023-09-07T12:27:43Z day: '30' ddc: - '530' degree_awarded: PhD department: - _id: GeKa doi: 10.15479/AT:ISTA:th_1033 file: - access_level: open_access checksum: b653b5216251f938ddbeafd1de88667c content_type: application/pdf creator: dernst date_created: 2019-04-09T07:13:28Z date_updated: 2020-07-14T12:46:35Z file_id: '6249' file_name: 2018_Thesis_Watzinger.pdf file_size: 85539748 relation: main_file - access_level: closed checksum: 39bcf8de7ac5b1bb516b11ce2f966785 content_type: application/zip creator: dernst date_created: 2019-04-09T07:13:27Z date_updated: 2020-07-14T12:46:35Z file_id: '6250' file_name: 2018_Thesis_Watzinger_source.zip file_size: 21830697 relation: source_file file_date_updated: 2020-07-14T12:46:35Z has_accepted_license: '1' language: - iso: eng month: '07' oa: 1 oa_version: Published Version page: '77' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria publist_id: '8005' pubrep_id: '1033' 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: Ge hut wires - from growth to hole spin resonance 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: '2018' ... --- _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' ...