Bipolaronic superconductivity out of a Coulomb gas

Abstract

Employing unbiased sign-problem-free quantum Monte Carlo, we investigate the effects of long-range Coulomb forces on BEC of bipolarons using a model of bond phonon-modulated electron hopping. In absence of long-range repulsion, this model was recently shown to give rise to small-size, light-mass bipolarons that undergo a superfluid transition at high values of the critical transition temperature $T_{\mathrm{c}}$. We find that $T_{\mathrm{c}}$ in our model even with the long-range Coulomb repulsion remains much larger than that of Holstein bipolarons, and can be on the order of or greater than the typical upper bounds on phonon-mediated $T_{\mathrm{c}}$ based on the Migdal-Eliashberg and McMillan approximations. Our work points to a physically simple mechanism for superconductivity in the low-density regime that may be relevant to current experiments on dilute superconductors.

5 pages, 5 figures

References in corpus (22)

• Tunable Phase Boundaries and Ultra-Strong Coupling Superconductivity in Mirror Symmetric Magic-Angle Trilayer Graphene
• Superconductivity in rhombohedral trilayer graphene
• Critical Temperature and Thermodynamics of Attractive Fermions at Unitarity
• Efficient DMFT-simulation of the Holstein-Hubbard Model
• Gate-controlled BCS-BEC crossover in a two-dimensional superconductor
• Two-dimensional Hubbard-Holstein bipolaron
• Superlight small bipolarons in the presence of strong Coulomb repulsion
• Bipolaronic high-temperature superconductivity
• Valence-bond solid to antiferromagnet transition in the two-dimensional Su-Schrieffer-Heeger model by Langevin dynamics
• Phase Diagram of the Su-Schrieffer-Heeger-Hubbard model on a square lattice
• Antiferromagnetism induced by electron-phonon-coupling
• Spin-triplet superconductivity from interband effect in doped insulators
• New mechanism and exact theory of superconductivity from strong repulsive interaction
• Unconventional superconductivity due to interband polarization
• Superconductivity, Charge-Density-Waves, and Bipolarons in the Holstein model
• Robustness of Antiferromagnetism in the Su-Schrieffer-Heeger-Hubbard model
• Peierls/Su-Schrieffer-Heeger polarons in two dimensions
• Bond-Peierls polaron: Moderate mass enhancement and current-carrying ground state
• Superconducting transition temperature of the Bose one-component plasma
• Bond Bipolarons: Sign-free Monte Carlo Approach
• A functional renormalization group study of the two dimensional Su-Schrieffer-Heeger-Hubbard model
• Phonon-modulated-hopping Polarons: X-representation Technique

Cited by in corpus (6)

• "Quantum bipolaron" superconductivity from quadratic electron-phonon coupling
• Semi-classical theory of bipolaronic superconductivity in a bond-modulated electron-phonon model
• Light polarons with electron-phonon coupling
• Magnonic Superconductivity
• Tuning competition between charge order and superconductivity in the square-lattice $t$-$t^{\prime }$-$J$ model
• Extrapolation of polaron properties to low phonon frequencies by Bayesian machine learning