Heavy-Electron Formation and Bipolaronic Transition in the Anharmonic Holstein Model
Abstract
The emergence of the bipolaronic phase and the formation of the heavy-electron state in the anharmonic Holstein model are investigated using the dynamical mean-field theory in combination with the exact diagonalization method. For a weak anharmonicity, it is confirmed that the first-order polaron-bipolaron transition occurs from the observation of a discontinuity in the behavior of several physical quantities. When the anharmonicity is gradually increased, the polaron-bipolaron transition temperature is reduced as well as the critical values of the electron-phonon coupling constant for polaron-bipolaron transition. For a strong anharmonicity, the polaron-bipolaron transition eventually changes to a crossover behavior. The effect of anharmonicity on the formation of the heavy-electron state near the polaron-bipolaron transition and the crossover region is discussed in detail.
Keywords
Cite
@article{arxiv.1110.0648,
title = {Heavy-Electron Formation and Bipolaronic Transition in the Anharmonic Holstein Model},
author = {Takahiro Fuse and Yoshiaki Ono and Takashi Hotta},
journal= {arXiv preprint arXiv:1110.0648},
year = {2012}
}
Comments
11 pages, 13 figures