Ordering of a Frustrated Spin S Ising Model as a Roughening Transition in SOS Model

摘要

We have shown that the ground-state problem of the spin 5 antiferromagnetic Ising model on the triangular lattice maps to a certain SOS model. For S < S_c approx 3 this SOS model is in a rough phase while for S > S_c it enters a flat phase. The rough phase, whose stability is examined, corresponds to the critical ground state of the Ising model. We suggest that the fiat phase corresponds to the ground state with a hidden long-range order.