Generation of Highly Pure Single-Photon State at Telecommunication Wavelength

TL;DR

This paper reports the successful generation of highly pure single-photon states at telecommunication wavelengths using advanced heralding techniques, enabling progress in quantum communication and information processing.

Contribution

It demonstrates the first generation of highly pure single-photon states at telecommunication wavelengths with record non-classicality measures.

Findings

Wigner negativity of -0.228±0.004 indicating strong non-classicality

Achieved 85.1±0.7% single-photon purity

Established a quantum-optics technology applicable to various quantum states

Abstract

Telecommunication wavelength with well-developed optical communication technologies and low losses in the waveguide are advantageous for quantum applications. However, an experimental generation of non-classical states called non-Gaussian states at the telecommunication wavelength is still underdeveloped. Here, we generate highly-pure-single-photon states, one of the most primitive non-Gaussian states, by using a heralding scheme with an optical parametric oscillator and a superconducting nano-strip photon detector. The Wigner negativity, the indicator of non-classicality, of the generated single photon state is $-0.228\pm0.004$, corresponded to $85.1\pm0.7\%$ of single photon and the best record of the minimum value at all wavelengths. The quantum-optics-technology we establish can be easily applied to the generation of various types of quantum states, opening up the possibility of continuous-variable-quantum-information processing at telecommunication wavelengths.