Abstract: The effect of heating electrons with respect to phonons in a thin superconducting film driven into the resistive state by the current and the external magnetic field has been observed and investigated. This effect caused by the electromagnetic radiation is manifested in the increased resistance of the film and is not selective over the frequency range from 1010 to 1015 Hz. That the effect is frequency independent under the conditions of strong electron scattering caused by static defects is explained by the decisive role of electron -electron collisions in forming the distribution function. The characteristic time of resistance change, obtained experimentally, corresponds to the relaxation time of the order parameter near the superconducting transition and to the relaxation time of the nonelastic electron-phonon interaction at lower temperatures and in lower magnetic fields.

Abstract: The creation of low noise heterodyne receivers for frequencies above 1 THz is in the urgentneed for radio astronomy, laser spectroscopy, plasma diagnostic, etc. In this paper we discussthe nonlinear effect related to hot electrons in superconductors, and their potential use in lownoise submilimeter wave mixer. We also discuss results achieved so far as well as possible futuredevelopments.