Polarization anisotropy and Zeeman splitting in strained quantum wires: Dimensional crossover effect on strain

Strain states in lattice-mismatched quantum wires have been studied by polarization analysis with a high magnetic field. Although biaxial strain should suppress quantum-confinement-induced in-plane linear polarization, large polarization is observed. This polarization remains even at a very high magnetic field, which shows that polarization is caused by non-biaxial (anisotropic triaxial) strain states in which the symmetry of the strain is broken. Circular polarization experiments show that Zeeman splitting is highly nonlinear to the field, which is also explained by the non-biaxial nature. These results can be understood as dimensional crossover on strain. (C) 1998 Elsevier Science B.V. All rights reserved.