TY  - JOUR
AU  - Murphy, A.
AU  - Semenov, A.
AU  - Korneev, A.
AU  - Korneeva, Y.
AU  - Gol'tsman, G.
AU  - Bezryadin, A.
PY  - 2015
DA  - 2015//
TI  - Three temperature regimes in superconducting photon detectors: quantum, thermal and multiple phase-slips as generators of dark counts
T2  - Sci. Rep.
JO  - Sci. Rep.
SP  - 10174 (1 to 10)
VL  - 5
KW  - SPD
KW  - SSPD
KW  - SNSPD
AB  - We perform measurements of the switching current distributions of three w approximately 120 nm wide, 4 nm thick NbN superconducting strips which are used for single-photon detectors. These strips are much wider than the diameter of the vortex cores, so they are classified as quasi-two-dimensional (quasi-2D). We discover evidence of macroscopic quantum tunneling by observing the saturation of the standard deviation of the switching distributions at temperatures around 2 K. We analyze our results using the Kurkijarvi-Garg model and find that the escape temperature also saturates at low temperatures, confirming that at sufficiently low temperatures, macroscopic quantum tunneling is possible in quasi-2D strips and can contribute to dark counts observed in single photon detectors. At the highest temperatures the system enters a multiple phase-slip regime. In this range single phase-slips are unable to produce dark counts and the fluctuations in the switching current are reduced.
SN  - 2045-2322
UR  - http://www.ncbi.nlm.nih.gov/pubmed/25988591
UR  - https://doi.org/10.1038/srep10174
DO  - 10.1038/srep10174
N1  - PMID:25988591; PMCID:PMC4437302
ID  - Murphy_etal2015
ER  -