"Transfer matrix in statistical mechanics"의 두 판 사이의 차이

수학노트
둘러보기로 가기 검색하러 가기
imported>Pythagoras0
imported>Pythagoras0
7번째 줄: 7번째 줄:
 
* so the partition function  is calculated in terms of the eigenvalues of the transfer matrix
 
* so the partition function  is calculated in terms of the eigenvalues of the transfer matrix
 
* then the problem of solving the model is reduced to the computation of this trace
 
* then the problem of solving the model is reduced to the computation of this trace
 
 
==정의==
 
* 스핀 $s_i, i=1,\cdots, N$과 주기조건 $s_{N+1}=s_1$을 가정
 
* 스핀 $s_i$과 $s_{i+1}$의 상호작용 $E(s_i,s_{i+1})$
 
* 해밀토니안이 $H=\sum_{i=1}^{N} E(s_i,s_{i+1})$ 꼴로 쓰여지는 경우
 
* 전달행렬은 $T_{s_i,s_{i+1}}=\exp(-\beta E(s_i,s_{i+1}))$ 꼴로 쓸 수 있으며, 분배함수는 다음과 같이 주어진다
 
$$
 
Z_N=\sum_{s_1,\cdots,s_N}T_{s_1,s_2}\cdots,T_{s_N,s_1}=\operatorname{Tr} T^N
 
$$
 
* 자유에너지(per site) 는 다음과 같다
 
$$
 
F=-\frac{1}{\beta}\lim_{N\to \infty}\frac{\ln \Lambda_0^N}{N}=-\frac{1}{\beta}\ln \Lambda_0,
 
$$
 
또는
 
$$
 
F=-\frac{1}{k T}\ln \Lambda_0,
 
$$
 
이 때 $\Lambda_0$는 $T$의 최대인 고유값
 
  
  
39번째 줄: 20번째 줄:
 
==transfer matrix of the six-vertex model==
 
==transfer matrix of the six-vertex model==
 
* [[Six-vertex model and Quantum XXZ Hamiltonian]]
 
* [[Six-vertex model and Quantum XXZ Hamiltonian]]
 
 
  
 
 
 
 

2013년 2월 19일 (화) 14:07 판

introduction

  • transfer matrix is builtup from matrices of  Boltzmann weights
  • trace of monodromy matrix is the transfer matrix
  • finding eigenvalues and eigenvectors of transfer matrix is crucial
  • Bethe ansatz equation is used to find the eigenvectors and eigenvalues of the transfer matrix
  • partition function = trace of power of transfer matrices
  • so the partition function  is calculated in terms of the eigenvalues of the transfer matrix
  • then the problem of solving the model is reduced to the computation of this trace


transfer matrix of the 1D Ising model


transfer matrix of the 2D Ising model


transfer matrix of the six-vertex model

 

related items

 

expositions