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arXiv · 2002.12381

Metal-insulator transition in a random Hubbard model

Grigory Tarnopolsky·Chenyuan Li·Darshan G. Joshi·Subir Sachdev
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Abstract

We examine the metal-insulator transition in a half-filled Hubbard model of electrons with random and all-to-all hopping and exchange, and an on-site non-random repulsion, the Hubbard $U$. We argue that recent numerical results of Cha et al. (arXiv:2002.07181) can be understood in terms of a deconfined critical point between a disordered Fermi liquid and an insulating spin glass. We find a deconfined critical point in a previously proposed large $M$ theory which generalizes the SU(2) spin symmetry to SU($M$), and obtain exponents for the electron and spin correlators which agree with those of Cha et al. We also present a renormalization group analysis, and argue for the presence of an additional metallic spin glass phase at half-filling and small $U$.

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Grigory Tarnopolsky, Chenyuan Li, Darshan G. Joshi, Subir Sachdev. 2020-02-27. Metal-insulator transition in a random Hubbard model. https://doi.org/10.1103/physrevb.101.205106

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