Quantum properties of dichroic silicon vacancies in silicon carbide

TL;DR

This paper explores the optical and spin properties of the V1 silicon vacancy defect in silicon carbide, demonstrating its potential for quantum technology applications due to its coherent optical emission and long spin coherence times.

Contribution

It provides a detailed investigation of the V1 defect's optical and spin characteristics, highlighting its suitability for spin-photon interfaces in quantum devices.

Findings

Up to 40% of emission into the zero-phonon line

Strong optical spin signal observed

Long spin coherence times measured

Abstract

The controlled generation and manipulation of atom-like defects in solids has a wide range of applications in quantum technology. Although various defect centres have displayed promise as either quantum sensors, single photon emitters or light-matter interfaces, the search for an ideal defect with multi-functional ability remains open. In this spirit, we investigate here the optical and spin properties of the V1 defect centre, one of the silicon vacancy defects in the 4H polytype of silicon carbide (SiC). The V1 centre in 4H-SiC features two well-distinguishable sharp optical transitions and a unique S=3/2 electronic spin, which holds promise to implement a robust spin-photon interface. Here, we investigate the V1 defect at low temperatures using optical excitation and magnetic resonance techniques. The measurements, which are performed on ensemble, as well as on single centres, prove that this centre combines coherent optical emission, with up to 40% of the radiation emitted into the zero-phonon line (ZPL), a strong optical spin signal and long spin coherence time. These results single out the V1 defect in SiC as a promising system for spin-based quantum technologies.