Electron-phonon interaction for adiabatic anharmonic phonons
摘要
A model with Holstein-like electron-phonon coupling is studied in the limit of adiabatic phonons. The phonon distribution is anharmonic with two degenerate maxima. This model can be related to fermions in a correlated binary alloy and describes microscopic phase separation. We discuss the weak and strong electron-phonon coupling limit and present a qualitative phase diagram. In terms of the phononic displacements it consists of a homogeneous, an alternating, and a disordered phase. There is a first order phase transition between the homogeneous and the alternating phase, and second order phase transition between the alternating and the disordered phase. The opening of a gap inside the disordered phase is treated by a dynamical mean-field theory.
引用
@article{arxiv.cond-mat/0504688,
title = {Electron-phonon interaction for adiabatic anharmonic phonons},
author = {K. Ziegler and D. Schneider},
journal= {arXiv preprint arXiv:cond-mat/0504688},
year = {2007}
}
备注
11 pages, 3 figures, revised and published version