Single-spin readout using optomechanically induced transparency: Application to readout of silicon-vacancy defects in diamond*

Solid-state defects are promising candidates to build quantum communication networks as well as powerful and versatile quantum sensors due to their small footprint and susceptibility to a variey of sensing targets. While some solid-state defects have excellent optical properties, others still lack a versatile method for high-fidelity single-shot optical readout. Yet, some of these defects couple to strain in the host material, which allows one to control the defect's state or even mechanical motion of the host material.

In this talk, we show that strain coupling can also be used as a resource to implement single-shot high-fidelity readout of a solid-state spin defect in a hybrid optomechanical system. By detuning the spins from the mechanical mode, one can engineer a dispersive spin-mechanical coupling, similar to dispersive readout in circuit QED (with the mechanical mode having the role of the microwave readout mode). Using an optomechanically-induced transparency (OMIT) measurement, the information on the spin state can be transduced to the optical output field and can be read out using conventional homodyne detection. Importantly, the OMIT scheme allows one to drive the mechanical mode optically, enabling all-optical spin readout.

As a promising example, we analyze silicon-vacancy (SiV) defects coupled to a diamond optomechanical crystal, and we show that the estimated readout times are competitive with the best optical fluorescence readout times for SiV centers (in the absence of strain coupling).