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Plaquette Ground State in the Two-dimensional SU(4) Spin-Orbital Model

Mathias van den Bossche·Fu-Chun Zhang·Frederic Mila
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Abstract

In order to understand the properties of Mott insulators with strong ground state orbital fluctuations, we study the zero temperature properties of the SU(4) spin-orbital model on a square lattice. Exact diagonalizations of finite clusters suggest that the ground state is disordered with a singlet-multiplet gap and possibly low-lying SU(4) singlets in the gap. An interpretation in terms of plaquette SU(4) singlets is proposed. The implications for LiNiO_2 are discussed.

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Mathias van den Bossche, Fu-Chun Zhang, Frederic Mila. 2000-07-10. Plaquette Ground State in the Two-dimensional SU(4) Spin-Orbital Model. https://doi.org/10.1007/pl00011085

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