Investigation of dark counts in innovative materials for superconducting nanowire single-photon detector applications

Abstract

The phenomenon of dark counts in nanostripes of different superconductor systems such as high-temperature superconducting YBa 2 Cu 3 O 7-x and superconductor/ferromagnet hybrids consisting of either NbN/NiCu or YBa 2 Cu 3 O 7x /L 0.7 Sr 0.3 MnO 3 bilayers have been investigated. For NbN/NiCu the rate of dark-count transients have been reduced with respect to pure NbN nanostripes and the events were dominated by a single vortex entry from the edge of the stripe. In the case of nanostripes based on YBa 2 Cu 3 O 7-x , we have found that thermal activation of vortices was also, apparently, responsible for triggering dark-count signals.

Two-dimensional cuprate nanodetector with single telecom photon sensitivity at T = 20 K

“…To date, the highest operating temperature for an SNSPD is 11 K, demonstrated in a MgB 2 nanostrip [8]. Expanding single-photon detection to higher operating temperatures, longer wavelengths and faster response motivates the search for new material platforms [9][10][11]. In particular, van der Waals (vdW) heterostructures of 2D materials [12][13][14][15] and high-T c superconductors [9,[16][17][18][19][20][21][22][23][24] have received interest as candidates for the development of next-generation SNSPD's with increased capabilities.…”