The quasiparticle relaxation time in superconducting films has been measured as a function of temperature using the response of the complex conductivity to photon flux. For tantalum and aluminum, chosen for their difference in electron-phonon coupling strength, we find that at high temperatures the relaxation time increases with decreasing temperature, as expected for electron-phonon interactio...

The electron and phonon temperature distribution in semiconductors initially heated on the surface with a short laser pulse is calculated as a function of position and time. We solved the coupled one-dimensional heat diffusion equations for electron and phonon systems in the linear approximation in which the physical parameters of the sample are temperature independent. We also consider the hea...

We study spin relaxation in n-type bulk GaAs, due to the Dyakonov-Perel mechanism, using ensemble Monte Carlo methods. Our results confirm that spin relaxation time increases with the electronic density in the regime of moderate electronic concentrations and high temperature. We show that the electron-electron scattering in the non-degenerate regime significantly slows down spin relaxation. Thi...

We develop a theory of effects of electron-electron collisions on the Dyakonov-Perel’ spin relaxation in multi-valley quantum wells. It is shown that the electron-electron scattering rate which governs the spin relaxation is different from that in a single-valley system. The theory is applied to Si/SiGe (001)-grown quantum wells where two valleys are simultaneously populated by free carriers. T...