Room temperature coherent spin alignment of silicon vacancies in 4H- and 6H-SiC

TL;DR

This paper demonstrates room temperature optical control of silicon vacancy spins in silicon carbide, achieving coherent superpositions and long Rabi oscillations, advancing potential quantum technology applications.

Contribution

It reports the first room temperature optical spin alignment and coherence of silicon vacancies in 4H- and 6H-SiC, with two schemes of optical population control.

Findings

Silicon vacancy spins can be optically aligned at room temperature.

Rabi oscillations of silicon vacancy spins persist for over 80 microseconds.

Two different optical alignment schemes are demonstrated in 4H- and 6H-SiC.

Abstract

We report the realization of the optically induced inverse population of the ground-state spin sublevels of the silicon vacancies ($V_{\mathrm{Si}}$) in silicon carbide (SiC) at room temperature. The data show that the probed silicon vacancy spin ensemble can be prepared in a coherent superposition of the spin states. Rabi nutations persist for more than 80 $\mu$s. Two opposite schemes of the optical alignment of the populations between the ground-state spin sublevels of the silicon vacancy upon illumination with unpolarized light are realized in 4H- and 6H-SiC at room temperature. These altogether make the silicon vacancy in SiC a very favorable defect for spintronics, quantum information processing, and magnetometry.