Classical Heisenberg spins on a hexagonal lattice with Kitaev couplings
| Autor: | Chandra, Samarth, Ramola, Kabir, Dhar, Deepak |
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| Rok vydání: | 2010 |
| Předmět: | |
| Zdroj: | Phys. Rev. E 82, 031113 (2010) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevE.82.031113 |
| Popis: | We analyse the low temperature properties of a system of classical Heisenberg spins on a hexagonal lattice with Kitaev couplings. For a lattice of 2N sites with periodic boundary conditions, we show that the ground states form an (N+1) dimensional manifold. We show that the ensemble of ground states is equivalent to that of a solid-on-solid model with continuously variable heights and nearest neighbour interactions, at a finite temperature. For temperature T tending to zero, all ground states have equal weight, and there is no order-by-disorder in this model. We argue that the bond-energy bond-energy correlations at distance R decay as 1/R^2 at zero temperature. This is verified by Monte Carlo simulations. We also discuss the relation to the quantum spin-S Kitaev model for large S, and obtain lower and upper bounds on the ground state energy of the quantum model. Comment: 11 pages, 8 figures |
| Databáze: | arXiv |
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