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

We have realized quantized charge pumping using non-adiabatic single-electron pumps in dopant-free GaAs two-dimensional electron gases. 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 5 K, driven by a simple RF sine waveform. Fitting to a universal decay cascade model yields values for the figure of merit δ that compare favorably to reported modulation-doped GaAs pumps operating under similar conditions. The devices reported here are already suitable for optoelectronics applications, and further improvement could offer a route to a current standard that does not require sub-Kelvin temperatures and high magnetic fields.