Description
In this work we present a study on the dark counts rate in a NbTiN
Superconducting Nanowire Single Photon Detectros (SNSPD). The strip is 80nm wide, hence
we are in the 2D regime. We measure the distribution of the time intervals elapsed between two
consecutive dark pulses at 4,2K and we do not observe a simple Poisson distribution as expected
but a combination of two Poisson-like processes, occurring with two di erent rates. The two
measured dark counts rate exhibit a di erent dependence on the bias current: one process
dominates at lower bias and the other bocomes more prominent as the current increases. In
the scenario presented by Ejrnaes et al. [1], this result could con rm that, in this temperature
regime, dark counts are generated mainly by multiple consecutive
uctuation events. The result
can also be a footprint of two di erent process occurring in the nanostrip.
References
[1] Ejrnaes M, Salvoni D, Parlato L, Massarotti D, Caruso R, Tafuri F, Yang X Y, You L X, Wang Z, Pepe G P and Cristiano R 2019 Scientific Reports 9 8053
