Interference and interaction effects in adiabatic pumping through quantum dots

TL;DR

This paper investigates how interference and Coulomb interactions influence adiabatic quantum pumping in Aharonov-Bohm interferometers with quantum dots, revealing phase-coherent and purely quantum interference pumping mechanisms.

Contribution

It introduces a real-time formalism to analyze adiabatic pumping with Coulomb interactions non-perturbatively, highlighting novel interference-based pumping effects.

Findings

Single-dot AB interferometer exhibits phase-coherent peristaltic pumping.

Double-dot AB interferometer demonstrates a quantum interference-driven pumping mechanism.

Coulomb interactions are incorporated non-perturbatively in the analysis.

Abstract

In order to investigate the effects of interference and interaction in adiabatic pumping, we consider an Aharonov-Bohm (AB) interferometer with a quantum dot embedded either in one or in both arms. We employ a real-time formalism and we perform an expansion both in the tunnel-coupling strengths between dot and leads and in the pumping frequency, taking into account the Coulomb interaction non perturbatively. We find that pumping in a single-dot AB interferometer has a peristaltic but phase-coherent character. In a double-dot AB interferometer, we find a pumping mechanism that relies purely on quantum mechanical interference and has no classical counterpart.