Electrically driven singularity and control of carrier spin of a hybrid quantum well

Abstract

We propose a hybrid quantum well structure comprising a compressively strained layer and tensile-strained layer and find that the major band character of the valence band maximum can be switched between the heavy hole of the compressively strained layer and the light hole of the tensile-strained layer by application of an electric field. Remarkably, in the switching resonant region, we find that the $g$ factors of both heavy-hole and light-hole states become singular (i.e., there is discontinuous change between positive and negative extrema), which enables the extreme control of the hole spin of the hybrid quantum well by the electric field.