Ls. Brizhik et al., THE GROUND-STATE OF AN EXTRA ELECTRON INTERACTING WITH ACOUSTIC PHONONS IN A MOLECULAR CHAIN, Physics letters. A, 205(1), 1995, pp. 90-96
The ground state of a quasi-particle (exciton, electron or hole) inter
acting with acoustic phonons in a one-dimensional chain, is investigat
ed using the variational method. The diagram of states is obtained whi
ch shows the regions of the electron-phonon coupling constant and of t
he nonadiabaticity parameter where the ground state of a quasiparticle
is described as an almost free electron state, a ''small polaron'', o
r a spontaneously localized state. It is shown that the formation of a
soliton-like state has a threshold with respect to the value of the e
lectron-phonon interaction, whose critical value increases with increa
sing nonadiabaticity parameter.