A spin dephasing mechanism mediated by the interplay between the spin-orbit coupling and the asymmetrical confining potential in a semiconductor quantum dot

作者：Li, Rui^*

来源：Journal of Physics: Condensed Matter , 2018, 30(39): 395304.

DOI：10.1088/1361-648X/aadcb8

• quantum dot
• spin-orbit coupling
• dephasing
• charge noise

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 V-0 = 10 meV, we find the spin dephasing times are T*(2) = 7 mu s, 275 mu s, 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 V-0 = 5 meV, the spin depahsing times in the InSb, InAs, and GaAs quantum dots are decreased to T*(2) = 0.38 mu s, 18 mu s, and 9 ms, respectively.

• 出版日期2018-10-3
• 单位燕山大学