Interaction quench in the Holstein model: Thermalization crossover from electron- to phonon-dominated relaxation

摘要: We study the relaxation of Holstein model after a sudden switch-on interaction by means nonequilibrium dynamical mean field theory, with self-consistent Migdal approximation as an impurity solver. show that there exists qualitative change in thermalization dynamics is varied weak-coupling regime. On weaker side this crossover, phonon oscillations are damped more rapidly than electron time scale, determined from momentum distribution function. stronger side, electrons becomes faster damping. In regime, despite long-lived oscillations, thermalized realized temporarily. The origin ``thermalization crossover'' found here traced back to different behaviors and self-energies function electron-phonon coupling. addition, importance demonstrated comparing results those obtained simpler Hartree-Fock solver neglects self-energy. latter scheme does not properly describe evolution isolated systems.