Quantum adiabatic pumping by modulating tunnel phase in quantum dots

TL;DR

This paper investigates quantum adiabatic pumping in a ring of three quantum dots, revealing how the pumped charge varies with magnetic flux and control parameter trajectories, highlighting non-universal step-like behaviors.

Contribution

It derives explicit expressions for pumped charge in a quantum dot ring, linking flux modulation to charge transfer and uncovering non-universal step behaviors based on control parameter paths.

Findings

Pumped charge exhibits steplike behavior with flux variance.

Step heights depend on control parameter trajectories.

Physical origin explained via Fano resonance conditions.

Abstract

In a mesoscopic system, under zero bias voltage, a finite charge is transferred by quantum adiabatic pumping by adiabatically and periodically changing two or more control parameters. We obtained expressions for the pumped charge for a ring of three quantum dots (QDs) by choosing the magnetic flux penetrating the ring as one of the control parameters. We found that the pumped charge shows a steplike behavior with respect to the variance of the flux. The value of the step heights is not universal but depends on the trajectory of the control parameters. We discuss the physical origin of this behavior on the basis of the Fano resonant condition of the ring.