Mott Insulating States with Competing Orders in the Triangular Lattice Hubbard Model

Wietek A, Rossi R, Simkovic F, Klett M, Hansmann P, Ferrero M, Stoudenmire EM, Schaefer T, Georges A (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Physical Review X American Physical Society

Book Volume: 11

Journal Issue: 4

DOI: 10.1103/PhysRevX.11.041013

Abstract

The physics of the triangular lattice Hubbard model exhibits a rich phenomenology, ranging from a metal-insulator transition, intriguing thermodynamic behavior, and a putative spin liquid phase at intermediate coupling, ultimately becoming a magnetic insulator at strong coupling. In this multimethod study, we combine a finite-temperature tensor network method, minimally entangled thermal typical states (METTS), with two Green-function-based methods, connected-determinant diagrammatic Monte Carlo and cellular dynamical mean-field theory, to establish several aspects of this model. We elucidate the evolution from the metallic to the insulating regime from the complementary perspectives brought by these different methods. We compute the full thermodynamics of the model on a width-four cylinder using METTS in the intermediate to strong coupling regime. We find that the insulating state hosts a large entropy at intermediate temperatures, which increases with the strength of the coupling. Correspondingly, and consistently with a thermodynamic Maxwell relation, the double occupancy has a minimum as a function of temperature which is the manifestation of the Pomeranchuk effect of increased localization upon heating. The intermediate coupling regime is found to exhibit both pronounced chiral as well as stripy antiferromagnetic spin correlations. We propose a scenario in which time-reversal symmetry-broken states compete with stripy-spin states at lowest temperatures.

Authors with CRIS profile

Philipp Hansmann Professur für Theoretische Physik mit dem Schwerpunkt Molekulare Materialien

Involved external institutions

Simons Foundation US United States (USA) (US) Institut polytechnique de Paris (IP Paris) FR France (FR) Max-Planck-Institut für Festkörperforschung DE Germany (DE)

How to cite

APA:

Wietek, A., Rossi, R., Simkovic, F., Klett, M., Hansmann, P., Ferrero, M.,... Georges, A. (2021). Mott Insulating States with Competing Orders in the Triangular Lattice Hubbard Model. Physical Review X, 11(4). https://dx.doi.org/10.1103/PhysRevX.11.041013

MLA:

Wietek, Alexander, et al. "Mott Insulating States with Competing Orders in the Triangular Lattice Hubbard Model." Physical Review X 11.4 (2021).

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