The Calculations of 3-Dimensional Ising Model of Finite Width
Bin Cao, Wei -Shih Yang, Chunxiang Cui
Abstract
In order to calculate 3-dimensional Ising model, we develop a method to build a much smaller transfer matrix containing the largest eigenvalue from the original 2 N 1 N 2 ×2 N 1 N 2 matrix V 1 . Firstly, the transfer matrix V 1 is written as the linear combination of several basic vectors. Secondly, we divide the basic vectors into several subgroups. The multiplication of a basic vector and V 1 can be written as the linear combination of basic vectors from the same subgroup. Finally, we use a new transfer matrix V 2 to describe the relationship between basic vectors of the same subgroup. V 2 is much smaller than the original transfer matrix and contains the largest eigenvalue of V 1 . We use this method to calculate the specific heat per atom C pa and the magnetic momentum per atom M pa . The results show that there exists a pair of temperature and magnetic field intensity where the specific heat gets to its maximum value. When N 1 N 2 increases, the maximum value of specific heat becomes larger.