Potential-tunable quantum dot single-electron pump

We have investigated a metal-gated QD charge pump device whose potential profile can be controlled. The proposed pump is uniquely designed with several metallic gates on a GaAs/AlGaAs two-dimensional electron gas system. We find that the length of 1st current plateau depends on potential profile of the QD. Under optimal conditions, a quantized current plateau with estimated accuracy of ppm level for the output current of ~80 pA at 500 MHz is observed at 4.2 K in the absence of magnetic fields.