One-phonon relaxation of localized electronic states in anharmonic nanoparticles

摘要: There is currently great interest in the dynamics of electrons and phonons low- dimensional systems, where effects quantum confinement cause a dramatic difference their behaviour as compared with bulk systems. In this paper we consider localized electronic impurity state (an two-level system) linearly coupled to vibrational modes an isolated nanometre-scale insulating crystal, study phonon emission rate at frequencies less than that lowest internal mode, i.e., acoustic 'gap'. We show that, finite temperature, energy relaxation below gap can occur result anharmonic broadening modes, calculate frequency temperature dependence provided by mechanism.