Effect of Hund's rule coupling on SU(4) spin-orbital system

Abstract

We investigate the ground-state property of a one-dimensional two-orbital Hubbard model at quarter filling by numerical techniques such as the density-matrix renormalization group method and the exact diagonalization. When the Hund's rule coupling $J$ is zero, the model is SU(4) symmetric. In fact, both spin and orbital correlations have a peak at $q=\pi /2$, indicating an SU(4) singlet state with a four-site periodicity. On the other hand, with increasing $J$, it is found that the peak position of the orbital correlation changes to $q=\pi$, while that of the spin correlation remains at $q=\pi /2$. We briefly discuss how the SU(4) symmetry is broken by $J$.

2 pages, 2 figures, Proceedings of ICM2006 (August 20-25, 2006, Kyoto)

References in corpus (3)

• Colossal Magnetoresistant Materials: The Key Role of Phase Separation
• Effect of Hund coupling in the one-dimensional SU(4) Hubbard model
• Spin, charge, and orbital correlations in the one-dimensional t2g-orbital Hubbard model

Cited by in corpus (2)

• Deformation of SU(4) singlet spin-orbital state due to Hund's rule coupling
• Multipole correlations of $t_{2g}$-orbital Hubbard model with spin-orbit coupling