Non-adiabatic single-electron pump in a dopant-free GaAs/AlGaAs 2DEG

TL;DR

This paper demonstrates a non-adiabatic single-electron pump in dopant-free GaAs/AlGaAs 2DEG that operates at high frequency and relatively high temperatures, with potential applications in optoelectronics and current standards.

Contribution

It introduces a dopant-free GaAs/AlGaAs 2DEG platform for single-electron pumping that functions under relaxed conditions, expanding practical applications.

Findings

Operates at up to 0.95 GHz frequency.

Works at temperatures up to 5K without magnetic field.

Performance compares favorably with modulation-doped GaAs pumps.

Abstract

We have realized quantized charge pumping using non-adiabatic single-electron pumps in dopant-free GaAs two-dimensional electron gases (2DEGs). The dopant-free III-V platform allows for ambipolar devices, such as p-i-n junctions, that could be combined with such pumps to form electrically-driven single photon sources. Our pumps operate at up to 0.95 GHz and achieve remarkable performance considering the relaxed experimental conditions: one-gate pumping in zero magnetic field and temperatures up to 5K, driven by a simple RF sine waveform. Fitting to a universal decay cascade model yields values for the figure of merit $\delta$ that compare favorably to reported modulation-doped GaAs pumps operating under similar conditions. The devices reported here are already suitable for optoelectronics applications, and with further improvement could offer a route to a current standard that does not require sub-Kelvin temperatures and high magnetic fields.