Li Rui
Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, People's Republic of China.
J Phys Condens Matter. 2018 Oct 3;30(39):395304. doi: 10.1088/1361-648X/aadcb8. Epub 2018 Aug 24.
Understanding the spin dephasing mechanism is of fundamental importance in all potential applications of the spin qubit. Here we demonstrate a spin dephasing mechanism in a semiconductor quantum dot due to the 1/f charge noise. The spin-charge interaction is mediated by the interplay between the spin-orbit coupling and the asymmetrical quantum dot confining potential. The dephasing rate is proportional to both the strength of the spin-orbit coupling and the degree of the asymmetry of the confining potential. For parameters typical of the InSb, InAs, and GaAs quantum dots with a moderate well-height [Formula: see text] meV, we find the spin dephasing times are [Formula: see text] μs, 275 μs, and 55 ms, respectively. In particular, the spin dephasing can be enhanced by lowering the well-height. When the well-height is as small as [Formula: see text] meV, the spin depahsing times in the InSb, InAs, and GaAs quantum dots are decreased to [Formula: see text] μs, 18 μs, and 9 ms, respectively.
理解自旋退相机制对于自旋量子比特的所有潜在应用至关重要。在此，我们展示了在半导体量子点中由于1/f电荷噪声导致的自旋退相机制。自旋-电荷相互作用由自旋-轨道耦合与不对称量子点限制势之间的相互作用介导。退相速率与自旋-轨道耦合强度和限制势的不对称程度成正比。对于具有中等阱高[公式：见正文]毫电子伏特的典型InSb、InAs和GaAs量子点参数，我们发现自旋退相时间分别为[公式：见正文]微秒、275微秒和55毫秒。特别地，通过降低阱高可以增强自旋退相。当阱高小至[公式：见正文]毫电子伏特时，InSb、InAs和GaAs量子点中的自旋退相时间分别降至[公式：见正文]微秒、18微秒和9毫秒。
