Title :
Mechanism of picosecond response of granular YBaCuO films to electromagnetic radiation
Author :
Gershenzon, E.M. ; Gol´tsman, G.N. ; Semenov, A.D. ; Sergeev, A.V.
Author_Institution :
Dept. of Phys., Moscow State Pedagogical Univ., USSR
fDate :
3/1/1991 12:00:00 AM
Abstract :
Ultrafast mechanisms of radiation detection in granular YBaCuO films are studied in the wide wavelength range from millimeter waves to near infrared. With an increase in radiation frequency, the Josephson detection at the grain-boundary weak links is replaced by electron heating into the grains. This change occurs in the submillimeter wavelength range. The electron-phonon relaxation time τeph is determined from direct measurements, quasi-stationary electron heating measurements, and the frequency dependence of the current at which maximum voltage shift is observed. The temperature dependence of τeph at T⩽40 K was found to be τeph ~T-1. The results show that detectors with a response time of a few picoseconds at nitrogen temperature are attainable
Keywords :
Josephson effect; barium compounds; grain boundaries; high-temperature superconductors; photodetectors; superconducting junction devices; superconducting thin films; yttrium compounds; Josephson detection; current; electromagnetic radiation; electron heating; electron-phonon relaxation time; frequency dependence; grain-boundary weak links; granular YBaCuO films; high temperature superconductor; maximum voltage shift; millimeter waves to near infrared; picosecond response; radiation detection; submillimeter wavelength range; Current measurement; Electrons; Frequency measurement; Heating; Infrared detectors; Millimeter wave measurements; Radiation detectors; Time measurement; Wavelength measurement; Yttrium barium copper oxide;
Journal_Title :
Magnetics, IEEE Transactions on
