Effect of Inversion Symmetry on the Band Structure of Semiconductor Heterostructures

Two classes of artificial semiconductor heterostructures, differing only in the inversion symmetry of their internal quantum wells, are studied via magnetotransport. The samples consist of GaAs/(AlGa) As layered structures containing two-dimensional hole systems. The results reveal a lifting of the spin degeneracy of the lowest hole subband in the samples with inversion asymmetric quantum wells. In those structures with symmetric wells the subband remains doubly degenerate.