Interacting electrons in a two-dimensional disordered environment: Effect of a Zeeman magnetic field

TL;DR

This study investigates how a Zeeman magnetic field influences the conducting properties of a disordered Hubbard model, revealing a field-induced metal-insulator transition consistent with experimental observations in 2D electron systems.

Contribution

It demonstrates that a Zeeman magnetic field can suppress metallic behavior and induce a metal-insulator transition in a disordered, interacting electron system, aligning with experimental data.

Findings

Zeeman field suppresses metallic behavior

Induces a metal-insulator transition at critical field

Qualitative agreement with experimental magnetoconductance

Abstract

The effect of a Zeeman magnetic field coupled to the spin of the electrons on the conducting properties of the disordered Hubbard model is studied. Using the Determinant Quantum Monte Carlo method, the temperature- and magnetic-field- dependent conductivity is calculated,as well as the degree of spin polarization. We find that the Zeeman magnetic field suppresses the metallic behavior present for certain values of interaction- and disorder- strength, and is able to induce a metal-insulator transition at a critical field strength. It is argued that the qualitative features of magnetoconductance in this microscopic model containing both repulsive interactions and disorder are in agreement with experimental findings in two-dimensional electron- and hole-gases in semiconductor structures.