Tuning Electron Spin States in Quantum Dots by Spin-Orbit Interactions

We theoretically investigate the influence of both Rashba spin-orbit interaction (RSOI) and Dresselhaus spin-orbit interaction (DSOI) on electron spin states, electron distribution and the optical absorption of a quantum dot. Our theoretical results show that the interplay between RSOI and DSOI results in an effective periodic potential, which consequently breaks the rotational symmetry and makes the quantum dot behave like two laterally coupled quantum dots. In the presence of RSOI and/or DSOI the spin is no longer a conserved quantity and its magnitude can be tuned by changing the strength of RSOI and/or DSOI. By reversing the direction of the perpendicular electric field, we can rotate the spatial distribution. This property provides us with a new way to control quantum states in a quantum dot by electrical means.