Quantized charge transport through a static quantum dot using a surface acoustic wave

TL;DR

This paper investigates how surface acoustic waves can induce quantized electron transport through a quantum dot, revealing a new low-power regime with resonant turnstile-like behavior and emphasizing the impact of quantum dot properties on current quantization.

Contribution

It introduces a novel low RF power regime where resonant transport occurs, highlighting the influence of quantum dot characteristics on quantized acoustoelectric current.

Findings

Resonant transport occurs at low RF power when wave amplitude matches charging energy.

Quantum dot properties significantly affect the number and width of quantized current plateaus.

High RF power results align with previous studies, but microscopic details shape the transport behavior.

Abstract

We present a detailed study of the surface acoustic wave mediated quantized transport of electrons through a split gate device containing an impurity potential defined quantum dot within the split gate channel. A new regime of quantized transport is observed at low RF powers where the surface acoustic wave amplitude is comparable to the quantum dot charging energy. In this regime resonant transport through the single-electron dot state occurs which we interpret as turnstile-like operation in which the traveling wave amplitude modulates the entrance and exit barriers of the quantum dot in a cyclic fashion at GHz frequencies. For high RF powers, where the amplitude of the surface acoustic wave is much larger than the quantum dot energies, the quantized acoustoelectric current transport shows behavior consistent with previously reported results. However, in this regime, the number of quantized current plateaus observed and the plateau widths are determined by the properties of the quantum dot, demonstrating that the microscopic detail of the potential landscape in the split gate channel has a profound influence on the quantized acoustoelectric current transport.