Anisotropic band structure of a parabolically confined electron system subjected to an in-plane magnetic field

Abstract

Abstract The anisotropy of the effective mass in a wide electron layer confined in a parabolic potential well has been determined from plasmon resonance experiments for the case of an in plane magnetic field. For this system, the resulting band structure can be described in terms of a hybridization of the electrical and the magnetic confinement and free motion in the plane of the electron system. The effective mass shows a strong anisotropic behaviour along the two principal directions with respect to the magnetic field. For a purely parabolic confining potential one can derive analytical expressions for this anisotropy which are in excellent agreement with the experimental results. Similarities to the collective excitation spectra of one-dimensional quantum wires are discussed.