Quantum transport properties of two-dimensional systems in disordered magnetic fields with a fixed sign

TL;DR

This study numerically examines quantum transport in two-dimensional disordered magnetic fields with a fixed sign, revealing unique conductivity behavior and oscillations in the weak disorder limit, differing from conventional zero-mean magnetic fields.

Contribution

It provides new insights into quantum transport under fixed-sign disordered magnetic fields, highlighting distinct conductivity behavior and oscillations not seen in zero-mean cases.

Findings

Conductivity remains around e^2/h in weak disorder.

Distinct behavior from conventional zero-mean magnetic fields.

Observation of Shubnikov-de Haas oscillations in weak disorder.

Abstract

Quantum transport in disordered magnetic fields is investigated numerically in two-dimensional systems. In particular, the case where the mean and the fluctuation of disordered magnetic fields are of the same order is considered. It is found that in the limit of weak disorder the conductivity exhibits a qualitatively different behavior from that in the conventional random magnetic fields with zero mean. The conductivity is estimated by the equation of motion method and by the two-terminal Landauer formula. It is demonstrated that the conductance stays on the order of $e^2/h$ even in the weak disorder limit. The present behavior can be interpreted in terms of the Drude formula. The Shubnikov-de Haas oscillation is also observed in the weak disorder regime.