|   | 
Details
   web
Records
Author Seleznev, V. A.; Divochiy, A. V.; Vakhtomin, Y. B.; Morozov, P. V.; Zolotov, P. I.; Vasil'ev, D. D.; Moiseev, K. M.; Malevannaya, E. I.; Smirnov, K. V.
Title Superconducting detector of IR single-photons based on thin WSi films Type Conference Article
Year 2016 Publication J. Phys.: Conf. Ser. Abbreviated Journal J. Phys.: Conf. Ser.
Volume 737 Issue Pages 012032
Keywords WSi SSPD, SNSPD, NEP
Abstract We have developed the deposition technology of WSi thin films 4 to 9 nm thick with high temperature values of superconducting transition (Tc~4 K). Based on deposed films there were produced nanostructures with indicative planar sizes ~100 nm, and the research revealed that even on nanoscale the films possess of high critical temperature values of the superconducting transition (Tc~3.3-3.7 K) which certifies high quality and homogeneity of the films created. The first experiments on creating superconducting single-photon detectors showed that the detectors' SDE (system detection efficiency) with increasing bias current (I b) reaches a constant value of ~30% (for X=1.55 micron) defined by infrared radiation absorption by the superconducting structure. To enhance radiation absorption by the superconductor there were created detectors with cavity structures which demonstrated a practically constant value of quantum efficiency >65% for bias currents Ib>0.6-Ic. The minimal dark counts level (DC) made 1 s-1 limited with background noise. Hence WSi is the most promising material for creating single-photon detectors with record SDE/DC ratio and noise equivalent power (NEP).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1742-6588 ISBN Medium
Area Expedition Conference (up)
Notes Approved no
Call Number Serial 1235
Permanent link to this record
 

 
Author Florya, I. N.; Korneeva, Y. P.; Mikhailov, M. Y.; Devizenko, A. Y.; Korneev, A. A.; Goltsman, G. N.
Title Photon counting statistics of superconducting single-photon detectors made of a three-layer WSi film Type Journal Article
Year 2018 Publication Low Temp. Phys. Abbreviated Journal Low Temp. Phys.
Volume 44 Issue 3 Pages 221-225
Keywords WSi SSPD, SNSPD
Abstract Superconducting nanowire single-photon detectors (SNSPD) are used in quantum optics when record-breaking time resolution, high speed, and exceptionally low levels of dark counts (false readings) are required. Their detection efficiency is limited, however, by the absorption coefficient of the ultrathin superconducting film for the detected radiation. One possible way of increasing the detector absorption without limiting its broadband response is to make a detector in the form of several vertically stacked layers and connect them in parallel. For the first time we have studied single-photon detection in a multilayer structure consisting of three superconducting layers of amorphous tungsten silicide (WSi) separated by thin layers of amorphous silicon. Two operating modes of the detector are illustrated: an avalanche regime and an arm-trigger regime. A shift in these modes occurs at currents of ∼0.5–0.6 times the critical current of the detector.

This work was supported by technical task No. 88 for scientific research at the National Research University “Higher School of Economics,” Grant No. 14.V25.31.0007 from the Ministry of Education and Science of Russia, and the work of G. N. Goltsman was supported by task No. 3.7328.2017/VU of the Ministry of Education and Science of Russia.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1063-777X ISBN Medium
Area Expedition Conference (up)
Notes Approved no
Call Number Serial 1310
Permanent link to this record
 

 
Author Vasilev, D. D.; Malevannaya, E. I.; Moiseev, K. M.; Zolotov, P. I.; Antipov, A. V.; Vakhtomin, Y. B.; Smirnov, K. V.
Title Influence of deposited material energy on superconducting properties of the WSi films Type Conference Article
Year 2020 Publication IOP Conf. Ser.: Mater. Sci. Eng. Abbreviated Journal IOP Conf. Ser.: Mater. Sci. Eng.
Volume 781 Issue Pages 012013 (1 to 6)
Keywords WSi SSPD, SNSPD
Abstract WSi thin films have the advantages for creating SNSPDs with a large active area or array of detectors on a single substrate due to the amorphous structure. The superconducting properties of ultrathin WSi films substantially depends on their structure and thickness as the NbN films. Scientific groups investigating WSi films mainly focused only on changes of their thickness and the ratio of the components on the substrate at room temperature. This paper presents experiments to determine the effect of the bias potential on the substrate, the temperature of the substrate, and the peak power of pulsed magnetron sputtering, which is the equivalent of ionization, a tungsten target, on the surface resistance and superconducting properties of the WSi ultrathin films. The negative effect of the substrate temperature and the positive effect of the bias potential and the ionization coefficient (peak current) allow one to choose the best WSi films formation mode for SNSPD: substrate temperature 297 K, bias potential -60 V, and peak current 3.5 A.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1757-899X ISBN Medium
Area Expedition Conference (up)
Notes Approved no
Call Number Serial 1798
Permanent link to this record