Partition function of the 3D Heisenberg model in the complex temperature plane

Abstract

We evaluate the partition function of the three-dimensional (3D) Heisenberg model on the simple cubic lattices in the complex temperature plane by using the Higher-Order Tensor Renormalization Group (HOTRG) method. As the system size increases, the magnitude of the partition function decreases much faster than in the case of the other models with α>0, which supports the argument that the heat capacity characteristics near the transition point is highly related to the partition function magnitude [Phys. Rev. E 96, 052130].