Dynamic nuclear polarization from current-induced electron spin polarization

TL;DR

This paper demonstrates that current-induced electron spin polarization can generate nuclear hyperpolarization via dynamic nuclear polarization, with measurable effects influenced by temperature, magnetic field, and voltage.

Contribution

It introduces a method to produce nuclear hyperpolarization using electric fields and electron spins, revealing the dependence on various experimental parameters.

Findings

Saturated nuclear fields of several millitesla are achieved.

The nuclear polarization depends asymmetrically on the relative alignment of spins and magnetic field.

The process occurs over approximately a hundred seconds.

Abstract

Current-induced electron spin polarization is shown to produce nuclear hyperpolarization through dynamic nuclear polarization. Saturated fields of several millitesla are generated upon the application of electric field over a timescale of a hundred seconds in InGaAs epilayers and measured using optical Larmor magnetometry. The dependence on temperature, external magnetic field, and applied voltage is investigated. We find an asymmetry in which the saturation nuclear field depends on the relative alignment of the electrically generated spin polarization and the external magnetic field, which we attribute to an interplay between various electron spin dynamical processes.