Large active-area superconducting microwire detector array with single-photon sensitivity in the near-infrared

TL;DR

This paper reports the development of a large active-area superconducting microwire detector array with single-photon sensitivity in the near-infrared, demonstrating high efficiency and scalability for advanced physics applications.

Contribution

It introduces the first SMSPD array with 8 pixels over 1 mm^2, showing saturated efficiency and single-photon sensitivity across all pixels, advancing detector scalability.

Findings

All devices achieved saturated internal detection efficiency at 1064 nm.

The silicon-rich WSi device detected single photons in all pixels.

Largest active-area SMSPD/SNSPD with near-IR sensitivity reported to date.

Abstract

Superconducting nanowire single photon detectors (SNSPDs) are the highest-performing technology for time-resolved single-photon counting from the UV to the near-infrared. The recent discovery of single-photon sensitivity in micrometer-scale superconducting wires is a promising pathway to explore for large active area devices with application to dark matter searches and fundamental physics experiments. We present 8-pixel $1 mm^2$ superconducting microwire single photon detectors (SMSPDs) with $1\,\mathrm{\mu m}$-wide wires fabricated from WSi and MoSi films of various stoichiometries using electron-beam and optical lithography. Devices made from all materials and fabrication techniques show saturated internal detection efficiency at 1064 nm in at least one pixel, and the best performing device made from silicon-rich WSi shows single-photon sensitivity in all 8 pixels and saturated internal detection efficiency in 6/8 pixels. This detector is the largest reported active-area SMSPD or SNSPD with near-IR sensitivity published to date, and the first report of an SMSPD array. By further optimizing the photolithography techniques presented in this work, a viable pathway exists to realize larger devices with $cm^2$-scale active area and beyond.