Interlayer-Interaction Dependence of Latent Heat in the Heisenberg Model on a Stacked Triangular Lattice with Competing Interactions

摘要

We study the phase transition behavior of a frustrated Heisenberg model on astacked triangular lattice by Monte Carlo simulations. The model has threetypes of interactions: the ferromagnetic nearest-neighbor interaction $J_1$ andantiferromagnetic third nearest-neighbor interaction $J_3$ in each triangularlayer and the ferromagnetic interlayer interaction $J_\perp$. Frustration comesfrom the intralayer interactions $J_1$ and $J_3$. We focus on the case that theorder parameter space is SO(3)$\times C_3$. We find that the model exhibits afirst-order phase transition with breaking of the SO(3) and $C_3$ symmetries atfinite temperature. We also discover that the transition temperature increasesbut the latent heat decreases as $J_\perp/J_1$ increases, which is opposite tothe behavior observed in typical unfrustrated three-dimensional systems.