Hole Zeeman effect in Ge/Si quantum dots

Abstract

We investigate theoretically the Zeeman effect on the lowest confined hole in quantum dots. In frame of tight-binding approach we propose a method of calculating the Lande factor for localized states. The principal values of the g-factor for the ground hole state in the self-assembled Ge/Si quantum dot are calculated. We find the strong g-factor anisotropy - the components gxx, gyy are one order smaller than the gzz-component, gzz=15.71, gxx=1.14, gyy=1.76. The efficiency of the developed method is demonstrated by calculating the size-dependence of g-factor and by establishment of the connectin with 2D case. The g-factor anisotropy increases with the island and the ground hole state g-factor goes to heavy hole g-factor. The analysis of the wave function structure shows that g-factor and its size-dependence are mainly controlled by the contribution of the state with Jz=±3/2.