Anharmonic Effect of Adiabatic Quantum Pumping

TL;DR

This paper investigates the anharmonic effects in adiabatic quantum pumping within double-barrier structures, revealing that the pumped current exhibits complex phase dependencies influenced by Berry curvature and loop trajectories.

Contribution

It introduces a systematic analysis of anharmonic effects in quantum pumping using the scattering matrix approach, highlighting the roles of Berry curvature and parameter loop trajectories.

Findings

Pumped current shows anharmonic phase dependence with double and higher harmonics.

Small driving amplitude ratios are not necessary for harmonic behavior.

Berry curvature and loop trajectory shape influence the current's harmonicity.

Abstract

Based on the scattering matrix approach, we systematically investigate the anharmonic effect of the pumped current in double-barrier structures with adiabatic time-modulation of two sinusoidal AC driven potential heights. The pumped current as a function of the phase difference between the two driven potentials looks like to be sinusoidal, but actually it contains sine functions of double and more phase difference. It is found that this kind of anharmonic effect of the pumped current is determined combinedly by the Be rry curvature and parameter variation loop trajectory. Therefore small ratio of the driving amplitude and the static amplitude is not necessary for harmonic pattern in the pumped current to dominate for smooth Berry curvature on the surface within the parameter variation loop.