Large nuclear Overhauser fields detected in vertically-coupled double quantum dots

TL;DR

This paper reports the detection of large nuclear Overhauser fields, up to 4 Tesla, indicating significant nuclear polarization in double quantum dots, achieved through electrical induction in a spin-blockade regime.

Contribution

It demonstrates the electrical induction and detection of large nuclear Overhauser fields in double quantum dots, with a phenomenological model explaining the results.

Findings

Largest Overhauser field observed was about 4 Tesla

Nuclear polarization reached approximately 40%

Phenomenological model provides qualitative understanding

Abstract

We report the electrical induction and detection of dynamic nuclear polarization in the spin-blockade regime of double GaAs vertical quantum dots. The largest Overhauser field observed was about 4 Tesla, corresponding to a nuclear polarization of about 40% in the present device. A phenomenological model is presented to provide a qualitative understanding of our results.