Single-parameter quantized charge pumping in high magnetic fields

TL;DR

This paper demonstrates that applying high magnetic fields enhances the precision of single-parameter quantized charge pumping in a semiconductor quantum dot, with improved current quantization observed up to full spin polarization conditions.

Contribution

It shows that high magnetic fields improve charge pumping quantization in quantum dots, extending the quantization stability to full spin polarization regimes.

Findings

Current plateaus become more pronounced at high magnetic fields.

Quantized current persists up to fields inducing full spin polarization.

Magnetic field enhances the accuracy of charge transfer in quantum dots.

Abstract

We study single-parameter quantized charge pumping via a semiconductor quantum dot in high magnetic fields. The quantum dot is defined between two top gates in an AlGaAs/GaAs heterostructure. Application of an oscillating voltage to one of the gates leads to pumped current plateaus in the gate characteristic, corresponding to controlled transfer of integer multiples of electrons per cycle. In a perpendicular-to-plane magnetic field the plateaus become more pronounced indicating an improved current quantization. Current quantization is sustained up to magnetic fields where full spin polarization of the device can be expected.