PT Journal
AU Korneeva, YP
   Manova, NN
   Florya, IN
   Mikhailov, MY
   Dobrovolskiy, OV
   Korneev, AA
   Vodolazov, DY
TI Different single-photon response of wide and narrow superconducting Mo[sub:x]Si[sub:1−x] strips
SO Phys. Rev. Applied
JI Phys. Rev. Applied
PY 2020
BP 024011 (1 to 7)
VL 13
IS 2
DI 10.1103/PhysRevApplied.13.024011
DE MoSi SSPD; SNSPD
AB The photon count rate (PCR) of superconducting single-photon detectors made of MoxSi1−x films shaped as a 2-μm-wide strip and a 115-nm-wide meander strip line is studied experimentally as a function of the dc biasing current at different values of the perpendicular magnetic field. For the wide strip, a crossover current Icross is observed, below which the PCR increases with an increasing magnetic field and above which it decreases. This behavior contrasts with the narrow MoxSi1−x meander, for which no crossover current is observed, thus suggesting different photon-detection mechanisms in the wide and narrow strips. Namely, we argue that in the wide strip the absorbed photon destroys superconductivity locally via the vortex-antivortex mechanism for the emergence of resistance, while in the narrow meander superconductivity is destroyed across the whole strip line, forming a hot belt. Accordingly, the different photon-detection mechanisms associated with vortices and the hot belt determine the qualitative difference in the dependence of the PCR on the magnetic field.
ER