A quantum spin liquid (QSL) is an exotic insulating phase with emergent gauge fields and fractionalized excitations. However, the unambiguous demonstration of the existence of a QSL in a "non-engineered" microscopic model (or in any material) remains challenging. Here, using numerically-exact sign-problem-free quantum Monte Carlo simulations, we show that a QSL arises in a non-engineered electron-phonon model. Specifically, we investigate the ground-state phase diagram of the bond Su-Schrieffer-Heeger (SSH) model on a 2D triangular lattice at half filling (one electron per site) which we show includes a QSL phase which is fully gapped, exhibits no symmetry-breaking order, and supports deconfined fractionalized holon excitations. This suggests new routes for finding QSLs in realistic materials and high-Tc superconductivity by lightly doping them.
@article{arxiv.2408.04002,
title = {Quantum spin liquid from electron-phonon coupling},
author = {Xun Cai and Zhaoyu Han and Zi-Xiang Li and Steven A. Kivelson and Hong Yao},
journal= {arXiv preprint arXiv:2408.04002},
year = {2025}
}