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arXiv · 2103.10560

Interaction-resistant metals in multicomponent Fermi systems

Andrea Richaud·Matteo Ferraretto·Massimo Capone
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Abstract

We analyze two different fermionic systems that defy Mott localization showing a metallic ground state at integer filling and very large Coulomb repulsion. The first is a multiorbital Hubbard model with a Hund's coupling, where this physics has been widely studied and the new metallic state is called a Hund's metal, and the second is a SU(3) Hubbard model with a patterned single-particle potential designed to display a similar interaction-resistant metal in a set-up which can be implemented with SU($N$) ultracold atoms. With simple analytical arguments and exact numerical diagonalization of the Hamiltonians for a minimal three-site system, we demonstrate that the interaction-resistant metal emerges in both cases as a compromise between two different insulating solutions which are stabilized by different terms of the models. This provides a strong evidence that the Hund's metal is a specific realization of a more general phenomenon which can be realized in various strongly correlated systems.

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Andrea Richaud, Matteo Ferraretto, Massimo Capone. 2021-03-18. Interaction-resistant metals in multicomponent Fermi systems. https://doi.org/10.1103/physrevb.103.205132

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