Spin relaxation assisted by optical phonon scattering in quantum dots: Dresselhaus versus Rashba spin–orbit coupling

Abstract

In the frame of the Huang–Rhys׳s model, we theoretically investigate the spin relaxation via longitudinal optical phonon scattering in quantum dots by considering the effect of lattice relaxation that arises from the electron-deformation potential acoustic phonon coupling. We find that the relaxation rate displays a cusp-like structure for both the Dresselhaus spin–orbit coupling (SOC) and Rashba SOC mechanisms. We compare the relaxation rates between these two mechanisms and find that the contribution of the Dresselhaus mechanism to the relaxation rate is one order of magnitude larger than the Rashba case at the same SOC strength. However, the same contribution can be obtained when the Rashba SOC strength is four times the Dresselhaus case. In addition, the influences of the external magnetic field and temperature on the relaxation rates are also qualitatively discussed.