Different quantization mechanisms in single-electron pumps driven by surface acoustic waves

TL;DR

This paper investigates the acoustoelectric current in single-electron pumps driven by surface acoustic waves, revealing two distinct quantization mechanisms and their coexistence under certain conditions.

Contribution

It identifies and characterizes two different quantization mechanisms in acoustoelectric current, a novel observation in the behavior of surface acoustic wave-driven single-electron pumps.

Findings

Two sets of quantized steps dominate current characteristics.

Both types of quantized steps can appear simultaneously.

Evidence suggests the presence of two independent quantization mechanisms.

Abstract

We have studied the acoustoelectric current in single-electron pumps driven by surface acoustic waves. We have found that in certain parameter ranges two different sets of quantized steps dominate the acoustoelectric current versus gate-voltage characteristics. In some cases, both types of quantized steps appear simultaneously though at different current values, as if they were superposed on each other. This could indicate two independent quantization mechanisms for the acoustoelectric current.