Adiabatic pumping through a quantum dot with coulomb interactions: A perturbation expansion in the tunnel coupling

TL;DR

This paper develops a diagrammatic real-time method to analyze adiabatic electron pumping through interacting quantum dots, revealing how Coulomb interactions and quantum fluctuations influence pumped charge.

Contribution

It introduces a systematic perturbation expansion in tunnel coupling for adiabatic pumping, highlighting the role of Coulomb interactions and quantum fluctuations in the process.

Findings

Coulomb interactions modify pumping characteristics via level renormalization.

Higher-order tunnel coupling contributions significantly affect pumped charge.

Interaction-dependent effects dominate when pumping through time-dependent tunnel couplings.

Abstract

We present a diagrammatic real-time approach to adiabatic pumping of electrons through interacting quantum dots. Performing a systematic perturbation expansion in the tunnel-coupling strength, we compute the charge pumped through a single-level quantum dot per pumping cycle. The combination of Coulomb interaction and quantum fluctuations, accounted for in contributions of higher order in the tunnel coupling, modifies the pumping characteristics via an interaction-dependent renormalization of the quantum-dot level. The latter is even responsible for the {\em dominant} contribution to the pumped charge when pumping via time-dependent tunnel-coupling strengths.