Optical polarization of nuclear spins in silicon carbide

TL;DR

This paper demonstrates room-temperature optical polarization of nuclear spins in silicon carbide, achieving near-complete polarization and providing a theoretical model for the process, with implications for quantum technologies and imaging.

Contribution

It introduces a method for optically polarizing nuclear spins in SiC and combines experimental and theoretical approaches to understand the underlying mechanisms.

Findings

Achieved 99% nuclear spin polarization at room temperature.

Developed a quantitative model linking hyperfine interactions to polarization.

Potential applications in quantum memories and magnetic resonance imaging.

Abstract

We demonstrate optically pumped dynamic nuclear polarization of 29-Si nuclear spins that are strongly coupled to paramagnetic color centers in 4H- and 6H-SiC. The 99 +/- 1% degree of polarization at room temperature corresponds to an effective nuclear temperature of 5 microKelvin. By combining ab initio theory with the experimental identification of the color centers' optically excited states, we quantitatively model how the polarization derives from hyperfine-mediated level anticrossings. These results lay a foundation for SiC-based quantum memories, nuclear gyroscopes, and hyperpolarized probes for magnetic resonance imaging.