Rapidly enhanced spin polarization injection in an optically pumped spin ratchet

TL;DR

This paper demonstrates a method to significantly increase the rate of nuclear spin polarization injection using optically pumped electrons in diamond, with implications for quantum information and sensing.

Contribution

It introduces a spin-ratchet mechanism leveraging high-power optical pumping to boost spin injection rates by over two orders of magnitude.

Findings

Boosted spin injection rates by over 100x

Identified bottlenecks in electron polarization and transfer

Achieved high-power optical polarization transfer in diamond

Abstract

Rapid injection of spin polarization into an ensemble of nuclear spins is a problem of broad interest, spanning dynamic nuclear polarization (DNP) to quantum information science. We report on a strategy to boost the spin injection rate by exploiting electrons that can be rapidly polarized via high-power optical pumping. We demonstrate this in a model system of Nitrogen Vacancy center electrons injecting polarization into a bath of 13C nuclei in diamond. We deliver >20W of continuous, nearly isotropic, optical power to the sample, constituting a substantially higher power than in previous experiments. Through a spin-ratchet polarization transfer mechanism, we show boosts in spin injection rates by over two orders of magnitude. Our experiments elucidate bottlenecks in the DNP process caused by rates of electron polarization, polarization transfer to proximal nuclei, and spin diffusion. This work demonstrates opportunities for rapid spin injection employing non-thermally generated electron polarization, and has relevance to a broad class of experimental systems including in DNP, quantum sensing, and spin-based MASERs.