Spin splitting in semiconductor heterostructures for<i>B→0</i>

Abstract

Spin splitting of subband states in semiconductor heterostructures at B=0 is ascribed to the inversion asymmetry--induced bulk ${\mathrm{k}}^{3}$ term, which dominates in large-gap materials, and to the interface spin-orbit or Rashba term, which becomes important in narrow-gap systems. We show for AlGaAs/GaAs heterostructures how this finite spin splitting at B=0 evolves from the Zeeman splitting for B\ensuremath{\ne}0 and predict a vanishing spin splitting at a finite -magnetic- field ---, which depends on the electron concentration in the inversion layer.