물리:평균장_이론

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
Next revisionBoth sides next revision
물리:평균장_이론 [2016/08/17 11:21] – [참고문헌] admin물리:평균장_이론 [2018/05/16 09:52] admin
Line 44: Line 44:
 $$e^{ax^2/2} = \sqrt{\frac{aN}{2\pi}} \int_{-\infty}^\infty dm~ e^{-Nam^2/2 + \sqrt{N}amx}$$ $$e^{ax^2/2} = \sqrt{\frac{aN}{2\pi}} \int_{-\infty}^\infty dm~ e^{-Nam^2/2 + \sqrt{N}amx}$$
 이므로 $a=\beta J$과 $x = \frac{1}{\sqrt{N}} \sum_i S_i$를 대입하면 이므로 $a=\beta J$과 $x = \frac{1}{\sqrt{N}} \sum_i S_i$를 대입하면
-$$e^{\frac{\beta J}{2} \frac{1}{N} \left( \sum_i S_i \right)^2} = \frac{\beta J N}{2\pi} \int_{-\infty}^\infty dm~ e^{-N\beta J m^2/2 + \beta J m \sum_i S_i$$+$$e^{\frac{\beta J}{2} \frac{1}{N} \left( \sum_i S_i \right)^2} = \frac{\beta J N}{2\pi} \int_{-\infty}^\infty dm~ e^{-N\beta J m^2/2 + \beta J m \sum_i S_i}$$
 이다. 여기에 대각합을 걸면 $\sum_i S_i$에만 걸리므로, 결과적으로 분배함수는 이다. 여기에 대각합을 걸면 $\sum_i S_i$에만 걸리므로, 결과적으로 분배함수는
 $$Z = \mbox{Tr} \sqrt{\frac{\beta J N}{2\pi}} \int_{-\infty}^\infty dm~ e^{-N\beta Jm^2/2 + \beta (Jm+h) \sum_i S_i}$$ $$Z = \mbox{Tr} \sqrt{\frac{\beta J N}{2\pi}} \int_{-\infty}^\infty dm~ e^{-N\beta Jm^2/2 + \beta (Jm+h) \sum_i S_i}$$
  • 물리/평균장_이론.txt
  • Last modified: 2023/09/05 15:46
  • by 127.0.0.1