High-temperature superconductivity induced by the Su-Schrieffer-Heeger electron-phonon coupling

TL;DR

This paper demonstrates through quantum Monte-Carlo simulations that SSH electron-phonon coupling models can achieve higher superconducting transition temperatures than Holstein models, due to their unique ability to induce strong pairing and phase coherence.

Contribution

The study provides the first systematic numerical evidence that SSH models can realize higher $T_c$ superconductivity, suggesting a promising pathway for discovering high-temperature superconductors.

Findings

SSH models exhibit higher $T_c$ than Holstein models in strong coupling regimes.

SSH phonons facilitate both electron pairing and phase coherence.

Higher $T_c$ in SSH models may be relevant to real materials.

Abstract

Experimental quest for high-temperature and room-temperature superconductivity (SC) at ambient pressure has been a long-standing research theme in physics. It has also been desired to construct reliable microscopic mechanisms that may achieve high-temperature SC. Here we systematically explore SC in the Su-Schrieffer-Heeger (SSH) electron-phonon coupling models by performing numerically-exact quantum Monte-Carlo simulations. Our results reliably showed that superconducting $T_c$ of the SSH models is high, remarkably higher than those in the Holstein models, particularly in strong electron-phonon coupling regime. This is mainly because SSH phonons can not only induce strong pairing between electrons but also help the phase coherence of Cooper pairs, thus realizing higher $T_c$. As mechanism of higher-$T_c$ of the SSH models could be potentially relevant to realistic materials, it paves a promising way to find higher-temperature SC in the future.