English

Polaron dynamics with a multitude of Davydov D$_2$ trial states

Chemical Physics 2015-07-08 v1 Quantum Gases Statistical Mechanics Strongly Correlated Electrons

Abstract

We propose an extension to the Davydov D2_2 Ansatz in the dynamics study of the Holstein molecular crystal model with diagonal and off-diagonal exciton-phonon coupling using the Dirac-Frenkel time-dependent variational principle. The new trial state by the name of the "multi-D2_2 Ansatz" is a linear combination of Davydov D2_2 trial states, and its validity is carefully examined by quantifying how faithfully it follows the Schr\"odinger equation. Considerable improvements in accuracy have been demonstrated in comparison with the usual Davydov trial states, i.e., the single D1_1 and D2_2 Ans\"atze. With an increase in the number of the Davydov D2_2 trial states in the multi-D2_2 Ansatz, deviation from the exact Schr\"odinger dynamics is gradually diminished, leading to a numerically exact solution to the Schr\"odinger equation.

Keywords

Cite

@article{arxiv.1507.01758,
  title  = {Polaron dynamics with a multitude of Davydov D$_2$ trial states},
  author = {Nengji Zhou and Zhongkai Huang and Jiangfeng Zhu and Vladimir Chernyak and Yang Zhao},
  journal= {arXiv preprint arXiv:1507.01758},
  year   = {2015}
}

Comments

14 pages, 15 figures