Cooperative enhancement of superconducting correlations by electron-electron and electron-phonon interactions in the quarter-filled band

Abstract

We present the results of Quantum Monte Carlo calculations for a two dimensional frustrated Hubbard model coupled to bond phonons. The model is known to have a d-wave superconducting ground state in the limit of large phonon frequency for sufficiently strong electron-phonon coupling. In the absence of electron-phonon coupling the Hubbard interaction U enhances superconducting pairing in the quarter-filled (density $\rho$ = 0.5) band. We show here that at $\rho$ = 0.5 electron-electron and electron-phonon interactions cooperatively reinforce d-wave pairing, while competing with each other at all other densities. Cooperative degrees of freedom are found in many phase transitions and are essential to understanding superconductivity in strongly correlated materials.

6 pages, 5 figures

References in corpus (12)

• Evidence for deconfined quantum criticality in a two-dimensional Heisenberg model with four-spin interactions
• Unconventional Superconductivity
• Theory of the striped superconductor
• Does Simple Two-Dimensional Hubbard Model Account for High-Tc Superconductivity in Copper Oxides?
• Gapless quantum spin liquid, stripe and antiferromagnetic phases in frustrated Hubbard models in two dimensions
• Hybrid-space density matrix renormalization group study of the doped two-dimensional Hubbard model
• Charge modulation, spin response, and dual Hofstadter butterfly in high-Tc cuprates
• Phase diagram of the one dimensional Hubbard-Holstein Model at 1/2 and 1/4 filling
• Superconducting d-wave stripes in cuprates: Valence bond order coexisting with nodal quasiparticles
• Temperature-driven transition from the Wigner Crystal to the Bond-Charge-Density Wave in the Quasi-One-Dimensional Quarter-Filled band
• Interplay of Site and Bond Electron-Phonon Coupling in One Dimension
• Crystalline electron pairs

Cited by in corpus (7)

• Bipolaronic high-temperature superconductivity
• Bipolaronic superconductivity out of a Coulomb gas
• Resonating Valence Bond States in an Electron-Phonon System
• Sr${}_2$RuO${}_4$, like doped cuprates and barium bismuthate, is a negative charge-transfer gap even parity superconductor with $\frac{3}{4}$-filled oxygen band
• Robust d-wave superconductivity from the Su-Schrieffer-Heeger-Hubbard model: possible route to high-temperature superconductivity
• Anomalous isotope Effect in d-wave superconductors on the square lattice
• Absence of superconductivity in the Hubbard dimer model for kappa-(BEDT-TTF)_2X