Mixing of Two-Electron Spin States in a Semiconductor Quantum Dot.

摘要

We show that the low-lying spin states of two electrons in a semiconductor quantum dot can be strongly mixed by electron-electron asymmetric exchange. This mixing is generated by the coupling of the electron spin to its orbital motion and to the relative orbital motion of the two electrons. The asymmetric exchange can be as large as 50% of the isotropic exchange, even for cylindrical dots. The resulting mixing can contribute to understanding spin dynamics in dots, such as recent observations of light polarization reversal.