Photo-galvanic effect in asymmetric quantum wells

Abstract

In this work we studied the charge carriers behaviour in quantum structures where the symmetry with respect to space coordinates and time-reversal symmetry are broken simultaneously. As the models of such structures we considered finite triangular as well as finite semiparabolic quantum wells placed in external magnetic field. We have shown by numerical analysis that the energy spectra of charge carriers in such structures are anisotropic with respect to in-plane (transverse) motion ϵn(+kx) ≠ ϵn(−kx). This leads to the anisotropy of charge carriers in-plane momentum transfer which, in its turn leads to the anisotropy of photoconductivity σ(+kx) ≠ σ(−kx) and as it follows from our calculations, the effect though not very great, could be measurable for the magnetic field of about few T.