NbN superconducting nanowire single photon detector with efficiency over 90% at 1550 nm wavelength operational at compact cryocooler temperature

TL;DR

This paper reports a NbN-based superconducting nanowire single photon detector achieving over 90% efficiency at 1550 nm wavelength at temperatures accessible with compact cryocoolers, advancing practical quantum technology applications.

Contribution

Demonstration of a NbN SNSPD with over 90% efficiency at 1550 nm at 2.1K, operable with a compact cryocooler, showing high performance at accessible temperatures.

Findings

Achieved 90.2% system detection efficiency at 1550 nm.

Efficiency saturated to 92.1% at 1.8K.

Operates effectively at temperatures accessible with compact cryocoolers.

Abstract

The fast development of superconducting nanowire single photon detector (SNSPD) in the past decade has enabled many advances in quantum information technology. The best system detection efficiency (SDE) record at 1550 nm wavelength was 93% obtained from SNSPD made of amorphous WSi which usually operated at sub-kelvin temperatures. We first demonstrate SNSPD made of polycrystalline NbN with SDE of 90.2% for 1550 nm wavelength at 2.1K, accessible with a compact cryocooler. The SDE saturated to 92.1% when the temperature was lowered to 1.8K. The results lighten the practical and high performance SNSPD to quantum information and other high-end applications.