Demonstration of Single Photon Detection in Amorphous Molybdenum Silicide / Aluminium Superconducting Nanostrip

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

“…The distance between the device and a standard single mode SMF 28 fiber is about 1 cm, providing a uniform illumination on the detector area. The single photon detection regime was already demonstrated in [21] for the nanomeanders. In Fig.…”

“…In this work, we explore the photoresponse at λ = 1550 nm and the dark counts in a liquid helium dewar at 4.2 K of a 9 nm thick MoSi covered with a very thin (2 nm) layer of Al, in two different configurations: nanomeanders 140 nm wide, previously demonstrated to work as single photon detector [21], and microstrips 2 μm wide. We observe that also the 9 nm thick MoSi/Al microstrip presents a good signal-to-noise ratio at 4.2 K, making these samples good candidates to be used as single photon detectors in liquid helium.…”

“…Fig.3Left: Measured dark pulse at T = 4.2 K when a strip 2 μm wide and 10 μm long was biased close to the critical current (the nanostrip pulse measured with different electronics can be found in[21]). Center: DCR vs normalized current at T = 4.2 K for a nanomeander (dark circle points) and a microstrip (red triangular points).…”

Investigation of NbRe for superconducting microstrips single photon detectors

“…The thickness of the deposited NbRe films is 4 nm, a value comparable with the superconducting coherence length of the material [24]. In order to prevent the oxidation of the NbRe surface, a 2 nm thick Al layer has been deposited ex-situ by DC magnetron sputtering at a rate of 0.3 nm/s [28]. The samples were patterned through optical lithography and argon ion etching.…”

Optimal configuration of a superconducting photon number resolving detector

“…These can be arranged according to an array, which proved to resolve the number of photons, acting as a PNRD [3]. Different materials and structures to improve the performance of SNSPDs have been investigated [4][5][6][7][8][9][10][11]. However, at 1550 nm, PNRD based on the NbN technology show high efficiency at relative high temperatures (T= 2 K) [3,12].…”