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

Article

关键词: CHARGE-DENSITY-WAVE;    MOLECULAR-CRYSTAL MODEL;    ELECTRON-PHONON MODEL;    PHASE-TRANSITIONS;    GAP FORMATION;    SPIN GAP;    SUPERCONDUCTIVITY;    SYSTEMS;    ANTIFERROMAGNETISM;    COMPETITION;   

DOI  :  10.1103/PhysRevB.98.085405

来源: SCIE

【 摘 要 】

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 T-c are explored.

【 授权许可】

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