Robust All-Optical Single-Shot Readout of NV Centers in Diamond

TL;DR

This paper introduces an all-optical method for single-shot readout of NV center spins in diamond that works effectively even with low photon collection efficiency, enhancing quantum sensing and computing applications.

Contribution

The authors develop a novel all-optical spin readout technique combining spin-dependent resonant excitation and spin-to-charge conversion for NV centers at cryogenic temperatures.

Findings

Achieves single-shot fidelity with less than 10^3 clicks/second

Works on shallow implanted NV centers suitable for sensing

Operates effectively without high-efficiency photon collection

Abstract

High-fidelity projective readout of a qubit's state in a single experimental repetition is a prerequisite for various quantum protocols of sensing and computing. Achieving single-shot readout is challenging for solid-state qubits. For Nitrogen-Vacancy (NV) centers in diamond, it has been realized using nuclear memories or resonant excitation at cryogenic temperature. All of these existing approaches have stringent experimental demands. In particular, they require a high efficiency of photon collection, such as immersion optics or all-diamond micro-optics. For some of the most relevant applications, such as shallow implanted NV centers in a cryogenic environment, these tools are unavailable. Here we demonstrate an all-optical spin readout scheme that achieves single-shot fidelity even if photon collection is poor (delivering less than 10$^3$ clicks/second). The scheme is based on spin-dependent resonant excitation at cryogenic temperature combined with spin-to-charge conversion, mapping the fragile electron spin states to the stable charge states. We prove this technique to work on shallow implanted NV centers as they are required for sensing and scalable NV-based quantum registers.