Charge-density-wave and pairing susceptibilities in a two-dimensional electron-phonon model

Abstract

We present quantum Monte Carlo results for a two-dimensional electron-phonon model. At half filling, a Peierls–charge-density-wave (CDW) instability dominates the behavior of the system and suppresses superconductivity. The CDW structure factor scales with system size and is consistent with a finite-size Ising-like scaling analysis which we use to estimate ${\mathit{T}}_{\mathit{c}}$ for the Peierls-CDW transition. Away from half filling, the Monte Carlo calculations show superconducting pairing in an s-wave channel, with a peak in the pair field susceptibility near a region in which there are strong Peierls-CDW correlations.