Rojas Onofre
Department of Physics, Institute of Natural Science, Federal University of Lavras, 37200-900, Lavras-MG, Brazil.
Phys Rev E. 2022 Jul;106(1-1):014109. doi: 10.1103/PhysRevE.106.014109.
We study the spin-1/2 Ising-XXZ model on a decorated honeycomb lattice composed of five spins per unit cell, one Ising spin, and four Heisenberg spins. This model involving the Heisenberg exchange interaction is one of the few models that can be exactly solvable through the generalized star-triangle transformation. The significance of this model is its close relationship to the fully decorated quantum Heisenberg honeycomb lattice since 4/5 of the particles are Heisenberg spins. We investigate the phase diagram at zero temperature and identify a relevant quantum spin frustrated phase resulting from the contribution of quantum Heisenberg exchange interaction. We obtain an exact residual entropy for the quantum spin frustrated phase, which coincides with the residual entropy of the antiferromagnetic spin-1/2 Ising model on a triangular lattice. We also thoroughly explore its thermodynamic properties, focusing mainly on the frustrated region such as entropy, specific heat, spontaneous magnetization, and critical temperature under several conditions.
我们研究了一种装饰蜂巢晶格上的自旋 - 1/2 伊辛 - XXZ 模型，该晶格每个晶胞由五个自旋组成，一个伊辛自旋和四个海森堡自旋。这个涉及海森堡交换相互作用的模型是少数几个可以通过广义星 - 三角变换精确求解的模型之一。该模型的重要性在于它与完全装饰的量子海森堡蜂巢晶格密切相关，因为 4/5 的粒子是海森堡自旋。我们研究了零温度下的相图，并确定了由量子海森堡交换相互作用的贡献导致的相关量子自旋受挫相。我们得到了量子自旋受挫相的精确剩余熵，它与三角晶格上反铁磁自旋 - 1/2 伊辛模型的剩余熵一致。我们还深入探讨了它的热力学性质，主要关注在几种条件下的受挫区域，如熵、比热、自发磁化和临界温度。
