High fidelity single-shot readout of qubits is a crucial component for fault-tolerant quantum computing and scalable quantum networks. In recent years, the nitrogen-vacancy (NV) center in diamond has risen as a leading platform for the above applications. The current single-shot readout of the NV electron spin relies on resonance fluorescence method at cryogenic temperature. However, the the spin-flip process interrupts the optical cycling transition, therefore, limits the readout fidelity. Here, we introduce a spin-to-charge conversion method assisted by near-infrared (NIR) light to suppress the spin-flip error. This method leverages high spin-selectivity of cryogenic resonance excitation and high flexibility of photonionization. We achieve an overall fidelity > 95% for the single-shot readout of an NV center electron spin in the presence of high strain and fast spin-flip process. With further improvements, this technique has the potential to achieve spin readout fidelity exceeding the fault-tolerant threshold, and may also find applications on integrated optoelectronic devices.
@article{arxiv.2009.14172,
title = {High-fidelity single-shot readout of single electron spin in diamond with spin-to-charge conversion},
author = {Qi Zhang and Yuhang Guo and Wentao Ji and Mengqi Wang and Jun Yin and Fei Kong and Yiheng Lin and Chunming Yin and Fazhan Shi and Ya Wang and Jiangfeng Du},
journal= {arXiv preprint arXiv:2009.14172},
year = {2023}
}