Random singlet-like phase of disordered Hubbard chains
Abstract
Local moment formation is ubiquitous in disordered semiconductors such as Si:P, where it is observed both in the metallic and the insulating regimes. Here, we focus on local moment behavior in disordered insulators, which arises from short-ranged, repulsive electron-electron interactions. Using density matrix renormalization group and strong-disorder renormalization group methods, we study paradigmatic models of interacting insulators: one dimensional Hubbard chains with quenched randomness. In chains with either random fermion hoppings or random chemical potentials, both at and away from half-filling, we find exponential decay of charge and fermion 2-point correlations but power-law decay of spin correlations that are indicative of the random singlet phase. The numerical results can be understood qualitatively by appealing to the large-interaction limit of the Hubbard chain, in which a remarkably simple picture emerges.
Cite
@article{arxiv.2206.03297,
title = {Random singlet-like phase of disordered Hubbard chains},
author = {Josephine Yu and Hong-Chen Jiang and Rahul Nandkishore and Srinivas Raghu},
journal= {arXiv preprint arXiv:2206.03297},
year = {2024}
}