Photon counting statistics of a superconducting single-photon detector made of a three-layer WSi film
I.N. Florya1, Yu.P. Korneeva1,5, M.Yu. Mikhailov2, A.Yu. Devizenko4, A.A. Korneev1,3, and G.N. Goltsman1,3
1Московский педагогический государственный университет ул. Малая Пироговская, 1, стр. 1, г. Москва, 119991, Россия
2B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Nauky Ave., Kharkiv 61103, Ukraine
3National Research University Higher School of Economics, Moscow 101000, Russia
4National Technical University “Kharkiv Polytechnic Institute”, 21 Bahaliy Str., Kharkov 61002, Ukraine
5Institute for Physics of Microstructures RAS, Nizhny Novgorod, 603950, Russia
Received October 27, 2017
Superconducting nanowire single-photon detectors (SNSPD) are successfully used in quantum optics, when a record-breaking time resolution, high speed and record low level of dark counts are required. However, the SNSPD detection efficiency is limited by the absorption coefficient of the radiation by the ultrathin superconducting film. One of the promising ways to increase the absorption in the detector without limiting its broadband is to make the detector in the form of several vertically stacked layers and connecting them in parallel. For the first time, we studied single-photon detection in a multi-layer structure consisting of three superconducting layers of amorphous tungsten silicide (WSi) separated by thin layers of amorphous silicon. We demonstrated two modes of operation of the detector: the avalanche regime and the arm-trigger regime, and determined that the regime change occurs in the bias current range of ~ 0.5-0.6 of the detector superconducting critical current.
PACS: 74.78.-w Superconducting films and low-dimensional structures
Key words: thin superconducting films, superconducting single photon detectors, detection efficiency, photon counting statistics, tungsten silicide.
Published online: January 25, 2018