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 semiconductorquantum dot can be strongly mixed by electron-electron asymmetric exchange.This mixing is generated by the coupling of electron spin to its orbital motionand to the relative orbital motion of the two electrons. The asymmetricexchange can be as large as 50% of the isotropic exchange, even for cylindricalquantum dots. The resulting spin mixing contributes to understanding spindynamics in quantum dots, including light polarization reversal.