Spontaneously induced irreversible energy transport in closed electron-phonon systems

Energy relaxation dynamics associated with the electron scattering process is investigated with a simple fully quantum model of an electron-phonon system. It is numerically demonstrated that contrary to traditional theories infinite numbers of phonon modes are not necessary and just a few phonon modes are sufficient for an irreversible energy transfer from the scattered electron to the phonon modes to be induced if the scattering potential is spatially irregular. Moreover, the phonon mode reaches promptly a thermalized state characterized by a well-defined temperature. The possibility that such a process might be an origin of resistivity in a closed quantum system is discussed.