Coulomb effects on the quantum transport of a two-dimensional electron system in periodic electric and magnetic fields

TL;DR

This paper investigates how Coulomb interactions influence quantum transport in a 2D electron system under periodic electric and magnetic fields, focusing on magnetoresistivity and Shubnikov-de Haas oscillations.

Contribution

It introduces a self-consistent screened Hartree-Fock approach to analyze Coulomb effects on spin splitting and edge states in modulated 2D electron systems.

Findings

Coulomb interactions cause strong screening and exchange effects.

The approach captures both spin splitting enhancement and edge state formation.

Results improve understanding of quantum transport in modulated 2D systems.

Abstract

The magnetoresistivity tensor of an interacting two-dimensional electron system with a lateral and unidirectional electric or magnetic modulation, in a perpendicular quantizing magnetic field, is calculated within the Kubo formalism. The influence of the spin splitting of the Landau bands and of the density of states (DOS) on the internal structure of the Shubnikov-de Haas oscillations is analyzed. The Coulomb electron - electron interaction is responsible for strong screening and exchange effects and is taken into account in a screened Hartree-Fock approximation, in which the exchange contribution is calculated self-consistently with the DOS at the Fermi level. This approximation describes both the exchange enhancement of the spin splitting and the formation of compressible edge strips, unlike the simpler Hartree and Hartree-Fock approximations, which yield either the one or the other.