High-fidelity single-shot readout of single electron spin in diamond with spin-to-charge conversion

TL;DR

This paper presents a novel spin-to-charge conversion technique with NIR assistance that significantly improves the fidelity of single-shot NV center electron spin readout in diamond, surpassing 95% fidelity at cryogenic temperatures.

Contribution

The authors introduce a new spin-to-charge conversion method assisted by near-infrared light, enhancing readout fidelity beyond previous resonance fluorescence techniques.

Findings

Achieved over 95% fidelity in single-shot readout of NV center electron spins.

Suppressed spin-flip errors using NIR-assisted spin-to-charge conversion.

Potential to reach fault-tolerant quantum computing thresholds.

Abstract

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.