The action of intense nonresonance laser radiation on the phase equilibrium of systems with coupled states*

Abstract

This paper analyzes the state of a bound two-electron formation (a bipolaron) in an electromagnetic radiation field that is not considered weak. By using the Kramers-Henneberger unitary transformation, the external, rapidly oscillating action is transferred to the argument of the potential energy. It is shown that increasing the external field intensity produces a monotonic decrease of the dissociation energy of a bound two-electron formation and reduces the number of its vibrational states. It is established that the external field produces attenuation of the electron-phonon interaction. The degree of dissociation of the bipolaron is computed as a function of the external field intensity, the temperature, and the concentration. The transition between the bound two-particle state and the single-particle state is treated as a smeared phase transition. © 2004 Optical Society of America