Point defects in SiC as a promising basis for single-defect, single-photon spectroscopy with room temperature controllable quantum states

TL;DR

This paper investigates silicon vacancy defects in silicon carbide, demonstrating their potential for room-temperature quantum applications like single-photon spectroscopy and spintronics, similar to NV centers in diamond.

Contribution

It provides experimental evidence that VSi-related defects in SiC exhibit NV-like quantum properties suitable for quantum technologies.

Findings

VSi defects can be optically aligned at room temperature

Spin states can be coherently superposed at room temperature

Zero-field ODMR enables spin manipulation with RF fields

Abstract

The unique quantum properties of the nitrogen-vacancy (NV) center in diamond have motivated efforts to find defects with similar properties in silicon carbide (SiC), which can extend the functionality of such systems not available to the diamond. Electron paramagnetic resonance (EPR) and optically detected magnetic resonance (ODMR) investigations presented here suggest that silicon vacancy (VSi) related point defects in SiC possess properties the similar to those of the NV center in diamond, which in turn make them a promising quantum system for single-defect and single-photon spectroscopy in the infrared region. Depending on the defect type, temperature, SiC polytype, and crystalline position, two opposite schemes have been observed for the optical alignment of the ground state spin sublevels population of the VSi-related defects upon irradiation with unpolarized light. Spin ensemble of VSi-related defects are shown to be prepared in a coherent superposition of the spin states even at room temperature. Zero-field ODMR shows the possibility to manipulate of the ground state spin population by applying radiofrequency field. These altogether make VSi-related defects in SiC very favorable candidate for spintronics, quantum information processing, and magnetometry.