Metal-insulator transition in a random Hubbard model

Journal Article · Tue May 05 00:00:00 EDT 2020 · Physical Review. B

DOI:https://doi.org/10.1103/physrevb.101.205106· OSTI ID:1803505

Tarnopolsky, Grigory ^[1]; Li, Chenyuan ^[2]; Joshi, Darshan G. ^[2]; Sachdev, Subir ^[2]

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1. Harvard Univ., Cambridge, MA (United States); OSTI
2. Harvard Univ., Cambridge, MA (United States)

In this work, 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 nonrandom repulsion, the Hubbard $$\textit{U}$$. We argue that recent numerical results of Cha et al. 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 $$\textit{M}$$ theory, which generalizes the SU(2) spin symmetry to SU($$\textit{M}$$) and obtains exponents for the electron and spin correlators which agree with those of Cha et al. This critical point is expected to have the maximal quantum Lyapunov exponent. We also present a renormalization group analysis, and argue for the presence of an additional metallic spin glass phase at half-filling and small $$\textit{U}$$.

• Research Organization: Harvard Univ., Cambridge, MA (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science (SC)
• Grant/Contract Number: SC0019030
• OSTI ID: 1803505
• Journal Information: Physical Review. B, Journal Name: Physical Review. B Journal Issue: 20 Vol. 101; ISSN 2469-9950
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
Materials Science
Physics