Interband absorption in quantum wires. II. Nonzero-magnetic-field case

We theoretically investigate a two-dimensional semiconductor system subjected to a periodic modulation in one lateral direction in a perpendicular magnetic field. Both type-I and type-II lateral superlattices are considered. The conduction and valence subbands as well as the polarization-dependent interband absorption are studied as a function of the strength V₁ of the lateral modulation. With increasing V₁, the optical transitions become increasingly anisotropic with respect to a polarization in the two-dimensional plane. Just as the calculated changes in the shape of the absorption spectrum, this reflects the continuous transition from a quasi-zero-dimensional characteristic to a quasi-one-dimensional characteristic of the electronic structure in the presence of a magnetic field.