Quantum pumping with adiabatically modulated barriers in graphene

TL;DR

This paper investigates how adiabatic quantum pumping in graphene, modulated by oscillating gates, depends on angle and energy, revealing current reversal due to Klein paradox effects.

Contribution

It introduces a detailed analysis of quantum pumping in graphene with out-of-phase gate modulations, highlighting the role of Klein paradox in current direction control.

Findings

Pumped current varies with angle and energy.

Current reversal occurs with high barriers due to Klein paradox.

Transparency differences influence pumping behavior.

Abstract

We study the adiabatic quantum pumping characteristics in the graphene modulated by two oscillating gate potentials out of phase. The angular and energy dependence of the pumped current is presented. The direction of the pumped current can be reversed when a high barrier demonstrates stronger transparency than a low one, which results from the Klein paradox. The underlying physics of the pumping process is illuminated.