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

Qi Zhang,Mengqi Wang,Fazhan Shi,Wentao Ji,Yuhang Guo,Ya Wang,Jun Yin,Fei Kong,Chunming Yin,Yiheng Lin,Jiangfeng Du

doi:10.1038/s41467-021-21781-5

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 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 flexibility of photoionization. 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.

Highlights

High fidelity single-shot readout of qubits is a crucial component for fault-tolerant quantum computing and scalable quantum networks
Resonance fluorescence method has become a commonly used method to achieve the single-shot readout of various solid-state spins such as quantum dot[1,2], rare-earth ions in crystals[3,4], silicon-vacancy center[5,6], and nitrogen-vacancy (NV) center[7] in diamond
Under spin-selective excitation of optical cycling transition, the spin state is inferred according to collected spin-dependent fluorescence photon counts

Summary

Introduction

High fidelity single-shot readout of qubits is a crucial component for fault-tolerant quantum computing and scalable quantum networks. Resonance fluorescence method has become a commonly used method to achieve the single-shot readout of various solid-state spins such as quantum dot[1,2], rare-earth ions in crystals[3,4], silicon-vacancy center[5,6], and nitrogen-vacancy (NV) center[7] in diamond. The accompanying spin non-conservation processes usually limit the optical readout window for photon collection and induce the spin state flip error. We demonstrate a new method to achieve a single-shot readout of NV center electron spin by combing a spin-selective photoionization process.

Results

Conclusion