In-Plane Magnetic Field Induced Anisotropy of 2D Fermi Contours and the Field Dependent Cyclotron Mass

TL;DR

This paper theoretically investigates how an in-plane magnetic field distorts the Fermi contours and affects the cyclotron mass of a 2D electron gas in a GaAs/AlGaAs heterostructure, revealing field-dependent anisotropies.

Contribution

It provides a self-consistent calculation of the field-dependent cyclotron mass and analyzes the shape deformation of Fermi contours under tilted magnetic fields.

Findings

In-plane magnetic field distorts Fermi contours from circular to anisotropic shapes.

Cyclotron mass varies with magnetic field and carrier concentration.

Potential for experimental detection of field-induced Fermi surface deviations.

Abstract

The electronic structure of a 2D gas subjected to a tilted magnetic field, with a strong component parallel to the GaAs/AlGaAs interface and a weak component oriented perpendicularly, is studied theoretically. It is shown that the parallel field component modifies the originally circular shape of a Fermi contour while the perpendicular component drive an electron by the Lorentz force along a Fermi line with a cyclotron frequency given by its shape. The corresponding cyclotron effective mass is calculated self-consistently for several concentrations of 2D carriers as a function of the in-plane magnetic field. The possibility to detect its field-induced deviations from the zero field value experimentally is discussed.