English

Two-dimensional Holstein-Hubbard model: Critical temperature, Ising universality, and bipolaron liquid

Strongly Correlated Electrons 2018-08-06 v3 Disordered Systems and Neural Networks Superconductivity

Abstract

The two-dimensional Holstein-Hubbard model is studied by means of continuous-time quantum Monte Carlo simulations. Using renormalization-group-invariant correlation ratios and finite-size extrapolation, the critical temperature of the charge-density-wave transition is determined as a function of coupling strength, phonon frequency, and Hubbard repulsion. The phase transition is demonstrated to be in the universality class of the two-dimensional Ising model and detectable via the fidelity susceptibility. The structure of the ground-state phase diagram and the possibility of a bipolaronic metal with a single-particle gap above TcT_c are explored.

Keywords

Cite

@article{arxiv.1709.01096,
  title  = {Two-dimensional Holstein-Hubbard model: Critical temperature, Ising universality, and bipolaron liquid},
  author = {Manuel Weber and Martin Hohenadler},
  journal= {arXiv preprint arXiv:1709.01096},
  year   = {2018}
}

Comments

8 pages, 9 figures; expanded version including Holstein-Hubbard results