Magnetotransport in Aharonov Bohm interferometers: Exact numerical simulations

TL;DR

This paper uses exact numerical simulations to study how many-body interactions affect magnetotransport symmetry in Aharonov-Bohm interferometers, revealing symmetry breaking and deviations from phenomenological models.

Contribution

It provides a detailed numerical analysis of nonlinear magnetotransport in Aharonov-Bohm interferometers with interactions, comparing exact results to phenomenological approaches.

Findings

Nonlinear transport coefficients obey specific magnetosymmetries depending on setup symmetry.

Phenomenological models capture symmetry behavior but differ in magnitude from exact simulations.

Interactions can break Onsager-Casimir symmetry away from linear response.

Abstract

The linear conductance of a two-terminal Aharonov-Bohm interferometer is an even function of the applied magnetic flux, as dictated by the Onsager-Casimir symmetry. Away from linear response this symmetry may be broken when many-body interactions are in effect. Using a numerically-exact simulation tool, we study the dynamics and the steady-state behavior of the out-of-equilibrium double-dot Aharonov Bohm interferometer, while considering different types of interactions: Model I includes a closed interferometer with an inter-dot electron-electron repulsion energy. In model II the interferometer is interacting with a dissipative environment, possibly driven away from equilibrium. In both cases we show that depending on the (horizontal, vertical) mirror symmetries of the setup, nonlinear transport coefficients obey certain magnetosymmetries. We compare numerically exact simulations to phenomenological approaches: The behavior of model I is compared to self-consistent mean-field calculations. Model II, allowing heat dissipation to a thermal bath, is mimicked by an Aharonov Bohm junction with a voltage probe. In both cases we find that phenomenological treatments capture the relevant transport symmetries, yet significant deviations in magnitude may show up.