Phase Diagram of the Spin-Orbital model on the Square Lattice
Abstract
We study the phase diagram of the spin-orbital model in both the weak and strong limits of the quartic spin-orbital exchange interaction. This allows us to study quantum phase transitions in the model and to approach from both sides the most interesting intermediate-coupling regime and in particular the SU(4)-symmetric point of the Hamiltonian. It was suggested earlier by Li et al [Phys.Rev.Lett. vol. 81, 3527 (1999)] that at this point the ground state of the system is a plaquette spin-orbital liquid. We argue that the state is more complex. There is plaquette order, but it is anisotropic: bonds in one direction are stronger than those in the perpendicular direction. This order is somewhat similar to that found recently in the frustrated J_1-J_2 Heisenberg spin model.
Cite
@article{arxiv.cond-mat/0105178,
title = {Phase Diagram of the Spin-Orbital model on the Square Lattice},
author = {E. Zasinas and O. P. Sushkov and J. Oitmaa},
journal= {arXiv preprint arXiv:cond-mat/0105178},
year = {2009}
}
Comments
8 pages, 4 Postscript figures