Gate modulation of the hole singlet-triplet qubit frequency in germanium
Abstract Spin qubits in germanium gate-defined quantum dots have made considerable progress within the last few years, partially due to their strong spin-orbit coupling and site-dependent g-tensors. While this characteristic of the g-factors removes the need for micromagnets and allows for the possi...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2025-01-01
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| Series: | npj Quantum Information |
| Online Access: | https://doi.org/10.1038/s41534-024-00953-3 |
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| author | John Rooney Zhentao Luo Lucas E. A. Stehouwer Giordano Scappucci Menno Veldhorst Hong-Wen Jiang |
| author_facet | John Rooney Zhentao Luo Lucas E. A. Stehouwer Giordano Scappucci Menno Veldhorst Hong-Wen Jiang |
| author_sort | John Rooney |
| collection | DOAJ |
| description | Abstract Spin qubits in germanium gate-defined quantum dots have made considerable progress within the last few years, partially due to their strong spin-orbit coupling and site-dependent g-tensors. While this characteristic of the g-factors removes the need for micromagnets and allows for the possibility of all-electric qubit control, relying on these g-tensors necessitates the need to understand their sensitivity to the confinement potential that defines the quantum dots. Here, we demonstrate a S − T_ qubit whose frequency is a strong function of the voltage applied to the barrier gate shared by the quantum dots. We find a g-factor that can be approximately increased by an order of magnitude adjusting the barrier gate voltage only by 12 mV. We show how this strong dependence could potentially be attributed to the dots moving through a variable strain environment in our device. This work not only reinforces previous findings that site-dependent g-tensors in germanium can be utilized for qubit manipulation, but reveals the sensitivity and tunability these g-tensors have to the electrostatic confinement of the quantum dot. |
| format | Article |
| id | doaj-art-8dda69a9d6eb4fdcb14e0d483bfc1e27 |
| institution | Kabale University |
| issn | 2056-6387 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | npj Quantum Information |
| spelling | doaj-art-8dda69a9d6eb4fdcb14e0d483bfc1e272025-02-02T12:35:48ZengNature Portfolionpj Quantum Information2056-63872025-01-011111710.1038/s41534-024-00953-3Gate modulation of the hole singlet-triplet qubit frequency in germaniumJohn Rooney0Zhentao Luo1Lucas E. A. Stehouwer2Giordano Scappucci3Menno Veldhorst4Hong-Wen Jiang5Physics and Astronomy Department, University of CaliforniaPhysics and Astronomy Department, University of CaliforniaQuTech and Kavli Institute of Nanoscience, Delft University of TechnologyQuTech and Kavli Institute of Nanoscience, Delft University of TechnologyQuTech and Kavli Institute of Nanoscience, Delft University of TechnologyPhysics and Astronomy Department, University of CaliforniaAbstract Spin qubits in germanium gate-defined quantum dots have made considerable progress within the last few years, partially due to their strong spin-orbit coupling and site-dependent g-tensors. While this characteristic of the g-factors removes the need for micromagnets and allows for the possibility of all-electric qubit control, relying on these g-tensors necessitates the need to understand their sensitivity to the confinement potential that defines the quantum dots. Here, we demonstrate a S − T_ qubit whose frequency is a strong function of the voltage applied to the barrier gate shared by the quantum dots. We find a g-factor that can be approximately increased by an order of magnitude adjusting the barrier gate voltage only by 12 mV. We show how this strong dependence could potentially be attributed to the dots moving through a variable strain environment in our device. This work not only reinforces previous findings that site-dependent g-tensors in germanium can be utilized for qubit manipulation, but reveals the sensitivity and tunability these g-tensors have to the electrostatic confinement of the quantum dot.https://doi.org/10.1038/s41534-024-00953-3 |
| spellingShingle | John Rooney Zhentao Luo Lucas E. A. Stehouwer Giordano Scappucci Menno Veldhorst Hong-Wen Jiang Gate modulation of the hole singlet-triplet qubit frequency in germanium npj Quantum Information |
| title | Gate modulation of the hole singlet-triplet qubit frequency in germanium |
| title_full | Gate modulation of the hole singlet-triplet qubit frequency in germanium |
| title_fullStr | Gate modulation of the hole singlet-triplet qubit frequency in germanium |
| title_full_unstemmed | Gate modulation of the hole singlet-triplet qubit frequency in germanium |
| title_short | Gate modulation of the hole singlet-triplet qubit frequency in germanium |
| title_sort | gate modulation of the hole singlet triplet qubit frequency in germanium |
| url | https://doi.org/10.1038/s41534-024-00953-3 |
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