An improved 2.5 GHz electron pump: single-electron transport through shallow-etched point contacts driven by surface acoustic waves

TL;DR

This paper reports an experimental advancement in 2.5 GHz electron pumps using surface acoustic waves, achieving highly accurate quantized current plateaus in a shallow-etched point contact, surpassing previous performance.

Contribution

The study demonstrates improved accuracy and higher current plateaus in a surface acoustic wave-driven electron pump using shallow-etched point contacts.

Findings

Up to 20 current plateaus observed at I=nef

Achieved accuracy of +/- 25 ppm on the first plateau

Enhanced performance over previous electron pump designs

Abstract

We present an experimental study of a 2.5 GHz electron pump based on the quantized acoustoelectric current driven by surface acoustic waves (SAWs) through a shallow-etched point contact in a GaAs/AlGaAs heterostructure. At low temperatures and with an additional counter-propagating SAW beam, up to n = 20 current plateaus at I=nef could be resolved, where n is an integer, e the electron charge, and f the SAW frequency. In the best case the accuracy of the first plateau at 0.40 nA was estimated to be dI/I = +/- 25 ppm over 0.25 mV in gate voltage, which is better than previous results.