Going beyond the linear approximation in describing electron- phonon coupling: relevance for the Holstein model

Abstract

Using the momentum average approximation we study the importance of adding higher-than-linear terms in the electron-phonon coupling on the properties of single polarons described by a generalized Holstein model. For medium and strong linear coupling, even small quadratic electron-phonon coupling terms are found to lead to very significant quantitative changes in the properties of the polaron, which cannot be captured by a linear Holstein Hamiltonian with renormalized parameters. We argue that the bi-polaron phase diagram is equally sensitive to addition of quadratic coupling terms if the linear coupling is large. These results suggest that the linear approximation is likely to be inappropriate to model systems with strong electron-phonon coupling, at least for low carrier concentrations.

6 pages, 4 figures Final version accepted into EPL

References in corpus (9)

• Interplay of electron-lattice interactions and superconductivity in Bi2Sr2CaCu2O8+d
• The Green's Function of the Holstein Polaron
• Two-dimensional Hubbard-Holstein bipolaron
• Interplay between electron-phonon and Coulomb interactions in cuprates
• Charge dynamics of doped holes in high Tc cuprates - A clue from optical conductivity
• Systematic improvement of the Momentum Average approximation for the Green's function of a Holstein polaron
• Distribution of Localized States from Fine Analysis of Electron Spin Resonance Spectra in Organic Transistors
• Investigating polaron transitions with polar molecules
• Quantum simulation of small-polaron formation with trapped ions

Cited by in corpus (18)

• Light-enhanced electron-phonon coupling from nonlinear electron-phonon coupling
• Relative importance of nonlinear electron-phonon coupling and vertex corrections in the Holstein model
• The polaron paradigm: a dual coupling effective band model
• Properties of the non-linear Holstein polaron at finite doping and temperature
• Discontinuous polaron transition in a two-band model
• Single polaron properties for double-well electron-phonon coupling
• The effect of dispersive optical phonons on the behaviour of a Holstein polaron
• Strongly bound yet light bipolarons for double-well electron-phonon coupling
• Polaron with Quadratic Electron-phonon Interaction
• A functional approach to the electronic and bosonic dynamics of many-body systems perturbed with an arbitrary strong electron-boson interaction
• "Quantum bipolaron" superconductivity from quadratic electron-phonon coupling
• Quantum Monte Carlo study of an anharmonic Holstein model
• Beyond the single-site approximation modeling of electron-phonon coupling effects on resonant inelastic X-ray scattering spectra
• Polaron and bipolaron tendencies in a semiclassical model for hole-doped bismuthates
• Soliton States From Quadratic Electron-Phonon Interaction
• Enhancement of Charge Density Wave Correlations in a Holstein Model with an Anharmonic Phonon Potential
• BLF-SSH Polarons coupled to Acoustic Phonons in the Adiabatic limit
• Polarons with arbitrary nonlinear electron-phonon interaction