Magnetic Moment Oscillations in a Quantum Hall Ring

TL;DR

This paper predicts oscillations in the magnetic moment of a quantum Hall ring caused by the interplay of currents, providing a new way to probe the current distribution in quantum Hall systems.

Contribution

It introduces the prediction of magnetic moment oscillations in a quantum Hall ring as a function of magnetic field, linking them to current distribution in the quantum Hall regime.

Findings

Oscillations depend on magnetic field and ring geometry.

Amplitude of oscillations is proportional to ring dimensions and cyclotron frequency.

Provides a direct method to probe quantum Hall current distribution.

Abstract

We predict non-mesoscopic oscillations in the orbital magnetic moment of a thin semiconductor ring in the quantum Hall effect regime. These oscillations, which occur as a function of magnetic field because of a competition between paramagnetic and diamagnetic currents in the ring, are a direct probe of the equilibrium current distribution in the nonuniform quantum Hall fluid. The amplitude of the oscillating moment in a thin ring with major radius $R$ and minor radius (half width) $a$ is approximately $a R e \omega_{\rm c} /c$, where $\omega_{\rm c}$ is the cyclotron frequency.