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arXiv:1712.08365 · Physical review. B./Physical review. B

Mott transition in the π -flux SU(4) Hubbard model on a square lattice

Zhichao Zhou, Congjun Wu, Yu Wang

Published May 14, 2018• 27 citations
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Abstract

With increasing repulsive interaction, we show that a Mott transition occurs from the semimetal to the valence bond solid, accompanied by the ${Z}_{4}$ discrete symmetry breaking. Our simulations demonstrate the existence of a second-order phase transition, which confirms the Ginzburg-Landau analysis. The phase transition point and the critical exponent $\ensuremath{\eta}$ are also estimated. To account for the effect of a $\ensuremath{\pi}$ flux on the ordering in the strong-coupling regime, we analytically derive by the perturbation theory the ring-exchange term, which is the leading-order term that can reflect the difference between the $\ensuremath{\pi}$-flux and zero-flux $SU(4)$ Hubbard models.

DOI
10.1103/physrevb.97.195122

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