Field theoretical approach to spin models

• 作者: Feng Liu Zhenhao Fan Zhipeng Sun Xuzong Chen Dingping Li
• 来源期刊: 物理学前沿
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: Condensed Matter&Materials Physics
• 页码范围: 108-114
• 页数: 7页
• 语种: 英文

摘要

We developed a systematic non-perturbative method base on Dyson-Schwinger theory and the Φ-derivable theory for Ising model at broken phase.Based on these methods,we obtain critical temper-ature and spin spin correlation beyond mean field theory.The spectrum of Green function obtained from our methods become gapless at critical point,so the susceptibility become divergent at Tc.The critical temperature of Ising model obtained from this method is fairly good in comparison with other non-cluster methods.It is straightforward to extend this method to more complicate spin models for example with continue symmetry.