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arXiv:2206.03297 · Physical review. B./Physical review. B

Random singlet-like phase of disordered Hubbard chains

Josephine J. Yu, Hong‐Chen Jiang, Rahul Nandkishore, S. Raghu

Published Aug 9, 2022• 3 citations
arXivHTMLPDF

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 disorder-averaged charge and fermion two-point correlations, but power-law decay of disorder-averaged 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.

DOI
10.1103/physrevb.106.075123

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