Nonthermal kinetic inductance photoresponse of thin superconducting films

Author

Heusinger, M.A. ; Semenov, A.D. ; Nebosis, R.S. ; Gousev, Y.P. ; Renk, K.F.

Author_Institution

Inst. fur Angewandte Phys., Regensburg Univ., Germany

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

2595

Lastpage

2598

Abstract

We report on the photoresponse of structured superconducting YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// and NbN films to femtosecond visible light pulses. The photoresponse signals obtained at temperatures below the transition temperature consist of a positive voltage peak of 25 ps width for the YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// sample and 40 ps for the NbN sample, each limited by the temporal resolution of the different setups, followed by a longer negative voltage transient. We attribute the photoresponse signals to a nonthermal change of the kinetic inductance of the superconducting films. We also present a model describing the dynamics of nonequilibrium quasiparticles (QP) and phonons, allowing to simulate our results. Our model provides the physical background for optimization of fast detectors based on the kinetic inductance photoresponse of thin superconducting films.<>

Keywords

barium compounds; high-temperature superconductors; inductance; niobium compounds; photovoltaic effects; quasiparticles; superconducting thin films; type II superconductors; yttrium compounds; 25 ps; 40 ps; NbN; YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//; YBa/sub 2/Cu/sub 3/O/sub 7/; fast detectors; femtosecond visible light pulses; nonequilibrium quasiparticles; nonthermal kinetic inductance photoresponse; superconducting films; voltage transient; Detectors; Inductance; Kinetic theory; Optical pulses; Phonons; Quadratic programming; Signal resolution; Superconducting films; Superconducting transition temperature; Voltage;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.403121

Filename

403121