Identification and tunable optical coherent control of transition-metal spins in silicon carbide

TL;DR

This paper demonstrates all-optical identification and control of molybdenum impurity spins in silicon carbide, revealing their potential for quantum communication at telecom wavelengths with coherent spin properties.

Contribution

It provides the first all-optical identification and coherent control of transition-metal impurity spins in silicon carbide at near-infrared wavelengths, with detailed spin and optical characterization.

Findings

Spin $S=1/2$ for ground and excited states.

Optical lifetimes of approximately 60 ns.

Inhomogeneous spin dephasing times around 0.3 microseconds.

Abstract

Color centers in wide-bandgap semiconductors are attractive systems for quantum technologies since they can combine long-coherent electronic spin and bright optical properties. Several suitable centers have been identified, most famously the nitrogen-vacancy defect in diamond. However, integration in communication technology is hindered by the fact that their optical transitions lie outside telecom wavelength bands. Several transition-metal impurities in silicon carbide do emit at and near telecom wavelengths, but knowledge about their spin and optical properties is incomplete. We present all-optical identification and coherent control of molybdenum-impurity spins in silicon carbide with transitions at near-infrared wavelengths. Our results identify spin $S=1/2$ for both the electronic ground and excited state, with highly anisotropic spin properties that we apply for implementing optical control of ground-state spin coherence. Our results show optical lifetimes of $\sim$60 ns and inhomogeneous spin dephasing times of $\sim$0.3 $\mu$s, establishing relevance for quantum spin-photon interfacing.