Hollmann, Arne and Struck, Tom and Langrock, Veit and Schmidbauer, Andreas and Schauer, Floyd and Leonhardt, Tim and Sawano, Kentarou and Riemann, Helge and Abrosimov, Nikolay and Bougeard, Dominique and Schreiber, Lars R. (2020) Large, Tunable Valley Splitting and Single-Spin Relaxation Mechanisms in a Si/SixGe1-x Quantum Dot. PHYSICAL REVIEW APPLIED, 13 (3): 034068. ISSN 2331-7019,
Full text not available from this repository. (Request a copy)Abstract
Valley splitting is a key feature of silicon-based spin qubits. Quantum dots in Si/SixGe1-x heterostructures reportedly suffer from a relatively low valley splitting, limiting the operation temperature and the scalability of such qubit devices. Here, we demonstrate a robust and large valley splitting exceeding 200 mu eV in a gate-defined single quantum dot, hosted in molecular-beam-epitaxy-grown Si-28/SixGe1-x. The valley splitting is monotonically and reproducibly tunable up to 15% by gate voltages, originating from a 6-nm lateral displacement of the quantum dot. We observe static spin relaxation times T-1 > 1 s at low magnetic fields in our device containing an integrated nanomagnet. At higher magnetic fields, T-1 is limited by the valley hotspot and by phonon noise coupling to intrinsic and artificial spin-orbit coupling, including phonon bottlenecking.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | QUBIT; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Huber > Group Dominique Bougeard |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 29 Mar 2021 07:10 |
| Last Modified: | 29 Mar 2021 07:10 |
| URI: | https://pred.uni-regensburg.de/id/eprint/44888 |
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