# Ising model

1. Dec 2, 2011

### matematikuvol

One line between (+-). Two lines between (++). Zero line between (--). $$\gamma$$ number of nearest neighbours. Why we have relation

$$\gamma N_+=2N_{++}+N_{+-}$$

Why we get this? Some explanation. This is from Kerson Huang.

File size:
6.9 KB
Views:
67
2. Nov 4, 2013

### 1ndranil

Choose a + site. Join it to each neighbor by a line. we need to draw gamma lines. Now do this for all + sites. So total lines = gamma*N(+). In this process i) between any (+,+) pair there will be two lines (one when we draw line from 1st + to 2nd +, other when we draw line from 2nd + to 1st +). Now there are N(++) number of (+,+) pair. So total lines between all (+,+) pair is 2N(++).. ii) between any (+,-) pair there will be one line (when drawn from + to -). There are N(+-) number of (+,-) pair. iii) between any (-,-) pair there will be no line. So total lines = 2N(++) + N(+-).

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted