Non-Equilibrium Magnetization in a Ballistic Quantum Dot

TL;DR

This paper demonstrates that time-dependent magnetic flux can suppress Aharonov-Bohm oscillations in ballistic quantum dots due to nonequilibrium electronic populations, providing a method to measure relaxation times.

Contribution

It reveals how dynamic magnetic flux affects quantum coherence in ballistic quantum dots and introduces a way to measure inelastic backscattering relaxation times.

Findings

AB oscillations are suppressed by time-dependent flux at high frequencies.

Nonequilibrium populations of coherent states cause the suppression.

The effect enables measurement of inelastic backscattering times.

Abstract

We show that Aharonov-Bohm (AB) oscillations in the magnetic moment of an integrable ballistic quantum dot can be destroyed by a time dependent magnetic flux. The effect is due to a nonequilibrium population of perfectly coherent electronic states. For real ballistic systems the equilibrization process, which involves a special type of inelastic electron backscattering, can be so ineffective, that AB oscillations are suppressed when the flux varies with frequency $\omega\sim$ 10$^7$-10$^8$ s$^{-1}$. The effect can be used to measure relaxation times for inelastic backscattering.