Conductance plateau transitions in quantum Hall wires with spatially correlated random magnetic fields

TL;DR

This paper numerically investigates how spatially correlated disordered magnetic fields affect quantum Hall wire conductance, revealing that correlations significantly alter edge state transport and conductance plateau transitions.

Contribution

It demonstrates that magnetic field correlations increase the separation between conductance plateau transitions and introduces an effective magnetic field concept based on maximum local fields.

Findings

Correlation increases separation between plateau transitions.

Transition energies align with Landau levels in an effective magnetic field.

Effective magnetic field relates to maximum local magnetic field in the system.

Abstract

Quantum transport properties in quantum Hall wires in the presence of spatially correlated disordered magnetic fields are investigated numerically. It is found that the correlation drastically changes the transport properties associated with the edge state, in contrast to the naive expectation that the correlation simply reduces the effect of disorder. In the presence of correlation, the separation between the successive conductance plateau transitions becomes larger than the bulk Landau level separation determined by the mean value of the disordered magnetic fields. The transition energies coincide with the Landau levels in an effective magnetic field stronger than the mean value of the disordered magnetic field. For a long wire, the strength of this effective magnetic field is of the order of the maximum value of the magnetic fields in the system. It is shown that the effective field is determined by a part where the stronger magnetic field region connects both edges of the wire.