Geometrical Pumping in Quantum Transport: Quantum Master Equation Approach

TL;DR

This paper develops a quantum master equation approach to analyze geometrical pumping in open quantum systems, revealing how control parameter modulation induces pumped currents characterized by Berry-phase-like quantities, with applications to quantum dots.

Contribution

It introduces a geometrical framework for quantum pumping using the quantum master equation, highlighting the role of interactions and reservoir modulations.

Findings

Geometrical pumping is absent for non-interacting electrons with only reservoir modulations.

Interactions between electrons enable geometrical pumping under the same conditions.

The formulation applies to systems with modulated chemical potentials and temperatures.

Abstract

For an open quantum system, we investigate the pumped current induced by a slow modulation of control parameters on the basis of the quantum master equation and full counting statistics. We find that the average and the cumulant generating function of the pumped quantity are characterized by the geometrical Berry-phase-like quantities in the parameter space, which is associated with the generator of the master equation. From our formulation, we can discuss the geometrical pumping under the control of the chemical potentials and temperatures of reservoirs. We demonstrate the formulation by spinless electrons in coupled quantum dots. We show that the geometrical pumping is prohibited for the case of non-interacting electrons if we modulate only temperatures and chemical potentials of reservoirs, while the geometrical pumping occurs in the presence of an interaction between electrons.