Destabilization of ferromagnetism by frustration and realization of a nonmagnetic Mott transition in the quarter-filled two-orbital Hubbard model

Abstract

The two-orbital Hubbard model on a square lattice at quarter filling (electron number per site $n=1$) is investigated by the variational Monte Carlo method. For the variational wave function, we include short-range doublon-holon binding factors. We find that the energy of this wave function is lower than that of the density-density Jastrow wave function partially including long-range correlations used in a previous study. We introduce frustration to the model by the next-nearest-neighbor hopping $t^{\prime }$ in addition to the nearest-neighbor hopping $t$. For $t^{\prime }=0$, a ferromagnetic state with staggered orbital order occurs by increasing the Coulomb interaction $U$ before the Mott transition takes place. By increasing $t^{\prime }$, the region of this ferromagnetic phase shrinks, and the Mott transition without magnetic order occurs.

7 pages, 7 figures

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Cited by in corpus (2)

• Weyl Semimetallic State in the Rashba-Hubbard Model
• Enhanced Spin-Orbit Coupling in a Correlated Metal