| 报告题目 | Dephasing of spin qubits (seminar) |
| 报告人 | Prof. Dimitrie Culcer |
| 报告人单位 | University of New South Wales, Australia |
| 报告时间 | 2014-12-05 |
| 报告地点 | 合肥微尺度物质科学国家实验室九楼会议室（9004室） |
| 主办单位 | 合肥微尺度物质科学国家实验室、国际功能材料量子设计中心 |
| 报告介绍 | Abstract： Spin-orbit coupling is ubiquitous in quantum dot quantum computing architectures, and makes spin qubits susceptible to charge noise. We derive a Hamiltonian describing the effect of spin-orbit and noise on a single-spin qubit in a quantum dot. Relaxation is due to noise coupling different orbital levels and is dominated by screened whole charge defects near the dot. Dephasing stems from noise causing relative fluctuations between orbital levels, and is driven by screened whole charge defects and unscreened dipole defects in the substrate. Dephasing times are vastly different between common materials such as Si and GaAs. They can be enhanced by increasing gate fields, choosing materials with weak spin-orbit such as Si, making dots narrower, or using accumulation dots. |
