Bond Bipolarons: Sign-free Monte Carlo Approach

Abstract

Polarons originating from phonon displacement modulated hopping have relatively light masses and, thus, are of significant current interest as candidates for bipolaron mechanism of high-temperature superconductivity [Phys. Rev. Lett. {\bf 121}, 247001 (2018)]. We observe that the bond model, when the dominant coupling comes from atomic vibrations on lattice bonds, can be solved by efficient sign-free Monte Carlo methods based on the path-integral formulation of the particle sector in combination with either the (real-space) diagrammatic or Fock-path-integral representation of the phonon sector. We introduce the corresponding algorithms and provide illustrative results for bipolarons in two dimensions. The results suggest that the route towards high-temperature superconductivity (if any) in the multiparametric space of the model lies between the Scylla of large size of moderately light bipolarons and Charybdis of large mass of compact bipolarons. As a result, on-site repulsion is helping $s$-wave superconductivity in sharp contrast with existing expectations.

5 pages, 4 figures

References in corpus (6)

• Normal state of a polarized Fermi gas at unitarity
• Two-dimensional Hubbard-Holstein bipolaron
• Zero Temperature Thermodynamics of Asymmetric Fermi Gases at Unitarity
• Peierls/Su-Schrieffer-Heeger polarons in two dimensions
• Bond-Peierls polaron: Moderate mass enhancement and current-carrying ground state
• Numerically Exact Generalized Green's Function Cluster Expansions for Electron-Phonon Problems

Cited by in corpus (5)

• Bipolaronic high-temperature superconductivity
• Phase Diagram of the Su-Schrieffer-Heeger-Hubbard model on a square lattice
• Superconducting transition temperature of the Bose one-component plasma
• Bipolaronic superconductivity out of a Coulomb gas
• Phonon-modulated-hopping Polarons: X-representation Technique