Multiphysics effects and electronic properties of anisotropic semiconductor quantum dots

摘要

In this paper we analyze a number of important coupled effects in semiconductor quantum dots with multiband models, including magneto-electromechanical coupling. We also demonstrate that the Rashba spin-orbit coupling may provide appreciable contributions to electronic properties of quantum dots by focusing on gate-controlled electron spins in quantum dots. In particular, we analyze the properties of anisotropic semiconductor quantum dots formed in the conduction band in the presence of the magnetic field. For this case, we formulate the Kane-type model and based on it we study the properties of dots by using both analytical and finite element techniques. It is shown that that in semiconductor quantum dots, the electron spin states in the phonon-induced spin-flip rate can be manipulated with the application of externally applied anisotropic gate potentials. The spin flip rates can be enhanced by such potentials, which can also reduce the level crossing points to lower quantum dot radii. We provide numerical examples providing further insight into these new findings where it is evident that these observed effects are due to the suppression of the g-factor towards bulk crystal. Based on these findings, the phonon induced spin-flip rate can be controlled through the application of spin-orbit coupling. Other coupled effects that affect the electronic properties of quantum dots are also discussed.