The isotropic limit of spin systems with orbital degeneracy has global SU(4) symmetry. On many 2D lattices, the ground state does not possess long-range order, which may explain the observed spin liquid properties of LiNiO₂. In the SU(4) N\'eel-ordered state, spin-spin correlations can be antiferromagnetic between two neighboring sites with parallel magnetic moments.
No takes yet. Share an insight, caveat, or question.
Li et al. (1998) studied this question.
Synapse has enriched 4 closely related papers on similar clinical questions. Consider them for comparative context: