Abstract: For the first time, measurements have been made on the electron energy relaxation time due to the electron--phonon interaction in films of the YBaCuO superconductor. The results indicate a significant intensification of the electron--phonon interaction in this compound as compared with normal superconducting metals.

Abstract: The time‐resolved luminescence spectra from excited conduction subbands in three samples of multi‐quantum‐well GaAs/AlxGa1-xAs (x=0.3 and 1) semiconductors with several well widths and barrier heights were obtained under high‐density excitations by a 30‐ps pulsed laser at 532 nm, which generated electron–hole pairs to the concentration of 1010–1013/cm2 per well per pulse at 77 K. The temperature and the Fermi energy of electron were determined by fitting best the constructed time‐resolved spectrum to the observed, and the time‐dependent electron energy was obtained by using these parameters. The energy‐loss rates of hot electrons are at least twice smaller than the calculated ones induced by the electron‐polar phonon scattering, including the screening effect due to the high carrier density.

Abstract: This review is devoted to the physics of current-carrying superconductors and normal metals having two or more stable states sustained by Joule self-heating. The creation, propagation, and localization of electrothermal domains and switching waves leading to the transition from one stable state to another in uniform and nonuniform samples are treated in detail. The connection between thermal bistability and hysteresis, dropping and stepped current-voltage characteristics, self-induced oscillations of current and voltage, selfreplication of electrothermal domains, and the formation of periodic and stochastic resistive structures are considered.