Quantum Monte Carlo study of an anharmonic Holstein model

Abstract

We study the effects of anharmonicity on the physics of the Holstein model, which describes the coupling of itinerant fermions and localized quantum phonons, by introducing a quartic term in the phonon potential energy. We find that the presence of this anharmonic term reduces the extent of the charge density wave phase (CDW) at half-filling as well as the transition temperature to this phase. Doping away from half-filling, we observe a first order phase transition between the CDW and a homogeneous phase which is also present in the harmonic model. In addition, we study the evolution of the superconducting susceptibility in the doped region and show that anharmonicity can enhance the superconducting response.

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Cited by in corpus (9)

• Fast and scalable quantum Monte Carlo simulations of electron-phonon models
• Stripe correlations in the two-dimensional Hubbard-Holstein model
• The two-dimensional $t$-$t^{\prime }$ Holstein model
• Kuramoto synchronization of quantum tunneling polarons for describing the dynamic structure in cuprate superconductors
• Enhancement of Charge Density Wave Correlations in a Holstein Model with an Anharmonic Phonon Potential
• Magnetic impurities in a charge-ordered background
• Polarons with arbitrary nonlinear electron-phonon interaction
• Charge correlations suppress unconventional pairing in the Holstein model
• Commensurate to Incommensurate Transition of Three Dimensional Charge Density Waves