The effects of non-linear electron-phonon interactions on superconductivity and charge-density-wave correlations

Abstract

Determinant quantum Monte Carlo (DQMC) simulations are used to study non-linear electron-phonon interactions in a two-dimensional Holstein-like model on a square lattice. We examine the impact of non-linear electron-lattice interactions on superconductivity and on Peierls charge-density-wave (CDW) correlations at finite temperatures and carrier concentrations. We find that the CDW correlations are dramatically suppressed with the inclusion of even a small non-linear interaction. Conversely, the effect of the non-linearity on superconductivity is found to be less dramatic at high temperatures; however, we find evidence that the non-linearity is ultimately detrimental to superconductivity. These effects are attributed to the combined hardening of the phonon frequency and a renormalization of the effective linear electron-phonon coupling towards weaker values. These results demonstrate the importance of non-linear interactions at finite carrier concentrations when one is addressing CDW and superconducting order and have implications for experiments that drive the lattice far from equilibrium.

5 Pages, 5 Figures

References in corpus (4)

• The Green's Function of the Holstein Polaron
• Ultrafast quenching of electron-boson interaction and superconducting gap in a cuprate superconductor
• The Swelling of Olympic Gels
• Strongly bound yet light bipolarons for double-well electron-phonon coupling

Cited by in corpus (7)

• Relative importance of nonlinear electron-phonon coupling and vertex corrections in the Holstein model
• The polaron paradigm: a dual coupling effective band model
• Polaron with Quadratic Electron-phonon Interaction
• 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
• Polarons with arbitrary nonlinear electron-phonon interaction