High-efficiency WSi superconducting nanowire single-photon detectors for quantum state engineering in the near infrared

TL;DR

This paper presents high-efficiency WSi superconducting nanowire single-photon detectors optimized for 1064 nm, achieving 93% efficiency and enabling advanced quantum state engineering with high heralding efficiency.

Contribution

The work introduces a highly efficient WSi SNSPD with 93% detection efficiency at 1064 nm, advancing quantum photonics applications.

Findings

Achieved 93% system detection efficiency at 1064 nm

Generated single photons with >90% heralding efficiency

Enabled high spectral brightness of $0.6\times10^4$ photons/(s·mW·MHz)

Abstract

We report on high-efficiency superconducting nanowire single-photon detectors based on amorphous WSi and optimized at 1064 nm. At an operating temperature of 1.8 K, we demonstrated a 93% system detection efficiency at this wavelength with a dark noise of a few counts per second. Combined with cavity-enhanced spontaneous parametric down-conversion, this fiber-coupled detector enabled us to generate narrowband single photons with a heralding efficiency greater than 90% and a high spectral brightness of $0.6\times10^4$ photons/(s$\cdot$mW$\cdot$MHz). Beyond single-photon generation at large rate, such high-efficiency detectors open the path to efficient multiple-photon heralding and complex quantum state engineering.