Classical polarons in a constant electric field -: art. no. 245203

A classical model of electrons interacting with a longitudinal optical (LO) continuum phonon field via the Frohlich coupling is studied. Simulating a spatially homogeneous excitation by initially,distributing the electrons on a lattice, the solution of the many-body problem reduces to the evaluation of one nonlocal integro-differential (vector) equation, which can be solved numerically. According to the two parameters governing the behavior-electric field and coupling constant-two different regimes can be distinguished, a diffusive and a ballistic one. In the critical range of transition from one regime to the other the influence of the electron density becomes crucial. It is shown that the electrons-via the interaction with the phonon field-emit radiation in the terahertz range around the LO-phonon frequency.