Investigation of Superconducting Molybdenum Silicide Nanostrips and Microstrips for Single Photon Detectors

Abstract

Superconducting nanostrip single photon detectors have emerged as the highest performing single-photon detectors; however, the possibility to use superconducting microstrip as single photon detectors is very appealing both to use them as larger areas detectors and for an easier technology in the manufacturing. The aim of this work is to test the photoresponse in liquid helium dewar of 9 nm thick MoSi covered with a very thin (2 nm) layer of Al, in two different configurations: nanomeanders and microstrips. We demonstrate that MoSi/Al microstrips can work as photodetectors also at T = 4.2 K. We also compare the dark count rate of the microstrip and the nanowire, confirming the lower noise for the microstrips also at 4.2 K.

Optimal configuration of a superconducting photon number resolving detector

“…Currently, the research is also oriented towards the realization of large-area devices [13,14] in innovative materials, which are sensitive to photons of even longer wavelengths. In particular, superconducting microstrip detectors have shown promising results [15][16][17][18], which could pave the way for the realization of photon number resolving devices based on them. In this work, we present the study of a meander-shaped superconducting NbN PNRD developed by Photec [19], based on an array of eight high efficiency NbN nanostrips which are suitable to work at a temperature of about 2 K. In particular, we measured the system detection efficiency (SDE) and the dark count rate (DCR) as the bias current increases.…”