Adiabatic charge pumping through a dot at the junction of N quantum wires

TL;DR

This paper investigates how adiabatic charge pumping occurs through a quantum dot at the junction of N quantum wires, analyzing the effects of varying tunneling parameters and phase differences on the pumped charge.

Contribution

It provides a detailed mapping of pumped charge patterns as functions of tunneling parameters and phase, revealing suppression effects with increasing number of wires and potential for charge tuning.

Findings

Maximum pumped charge decreases as the number of wires increases.

Pumped charge can be tuned by modulating couplings of the N-2 leads.

Explicit patterns of charge pumping depend on phase and tunneling parameters.

Abstract

We study adiabatic charge pumping through a quantum dot placed at the junction of $N$ quantum wires. We explicitly map out the pattern of pumped charge as a function of the time-varying tunneling parameters coupling the wires to the dot and the phase between any two time varying parameters controlling the shape of the dot. We find that with $N-2$ time-independent well-coupled leads, the maximum pumped charge in the remaining two leads is strongly suppressed with increasing $N$, leading to the possibility of tuning of the pumped charge, by modulating the coupling of the $N-2$ leads.