Gutzwiller scheme for electrons and phonons: the half-filled Hubbard-Holstein model

Abstract

We analyze the ground-state properties of strongly-correlated electrons coupled with phonons by means of a generalized Gutzwiller wavefunction which includes phononic degrees of freedom. We study in detail the paramagnetic half-filled Hubbard-Holstein model, where the electron-electron interaction can lead to a Mott transition, and the electron-phonon coupling to a bipolaronic transition. We critically discuss the quality of the proposed wavefunction in describing the various transitions and crossovers that occur as a function of the parameters. Previous variational attempts are recovered as particular choices of the wavefunction, while keeping all the variational freedom allows to access regions of the phase diagram otherwise inaccessible within previous variational approaches.

11 pages, 6 figures. Published version, minor changes in the discussion of the results

References in corpus (7)

• Interplay of electron-lattice interactions and superconductivity in Bi2Sr2CaCu2O8+d
• Efficient DMFT-simulation of the Holstein-Hubbard Model
• First- and Second Order Phase Transitions in the Holstein-Hubbard Model
• Phase diagram of the one dimensional Hubbard-Holstein Model at 1/2 and 1/4 filling
• Isotope effects in the Hubbard-Holstein model within dynamical mean-field theory
• Effects of the electron-phonon coupling near and within the insulating Mott phase
• Extended Gutzwiller wavefunction for the Hubbard-Holstein model

Cited by in corpus (6)

• Superconductivity, charge-density waves, antiferromagnetism, and phase separation in the Hubbard-Holstein model
• Interplay of charge, spin and lattice degrees of freedom on the spectral properties of the one-dimensional Hubbard-Holstein model
• Competing Correlated Insulators in multi-orbital systems coupled to phonons
• Dynamical effects on superconductivity in BCS-BEC crossover
• Intertwined fluctuations and isotope effects in the Hubbard-Holstein model on the square lattice from functional renormalization
• Phase diagram of the two-dimensional Hubbard-Holstein model: enhancement of $s$-wave pairing between charge and magnetic orders