Coherent control of the silicon-vacancy spin in diamond

TL;DR

This paper demonstrates the coherent control of a silicon-vacancy center's spin in diamond, measuring its coherence time and showing its potential for quantum information applications.

Contribution

It reports the first coherent control of a single silicon-vacancy center spin in diamond with microwave fields and measures its coherence properties at cryogenic temperatures.

Findings

Measured spin coherence time T2* of 115 ns at 3.6 K

Demonstrated optically detected magnetic resonance of the silicon-vacancy center

Identified phonon-mediated dephasing as a key decoherence mechanism

Abstract

Spin impurities in diamond have emerged as a promising building block in a wide range of solid-state-based quantum technologies. The negatively charged silicon-vacancy centre combines the advantages of its high-quality photonic properties with a ground-state electronic spin, which can be read out optically. However, for this spin to be operational as a quantum bit, full quantum control is essential. Here, we report the measurement of optically detected magnetic resonance and the demonstration of coherent control of a single silicon-vacancy centre spin with a microwave field. Using Ramsey interferometry, we directly measure a spin coherence time, T2*, of 115 +/- 9 ns at 3.6 K. The temperature dependence of coherence times indicates that dephasing and decay of the spin arise from single phonon-mediated excitation between orbital branches of the ground state. Our results enable the silicon-vacancy centre spin to become a controllable resource to establish spin-photon quantum interfaces.