Inelastic scattering time of electrons in disordered bismuth films: “dirty” limit
Abstract
The behavior of quantum corrections to the magnetic conductivity of thin bismuth films (of thickness ∼ 100 Å) associated with weak localization of electrons is studied in the temperature interval 0.3–10 K under conditions of electron overheating. The experimental data are used to obtain the temperature dependence of the time τeph of electron-phonon energy relaxation and the time τephi corresponding to the electron-phonon contribution to the phase relaxation of electrons. The theoretically predicted attenuation of electron-phonon interaction in the case of the inequality qphl <1 (qph is the wave vector of thermal phonon, and l is the electron mean free path) ensuring the “dirty” limit is detected experimentally for the first time. Two possibilities of realization of “dirty” limit are discussed, viz., an artificial decrease in the mean free path l and a decrease in temperature to a value below the characteristic temperature T2= ħsl,t/kl (sl,t is the phonon velocity) which has a value ≃1K for l≃100 Å. A transition is observed from the dependence τeph −1∝T3 to τeph1∝T4 is observed at a temperature of 1.2 K, which is in accord with the estimated value of T2 for the investigated objects.