PATH-INTEGRAL APPROACH TO THE HUBBARD-MODEL

Note

关键词: HIGH-TC SUPERCONDUCTIVITY;    FIELD-THEORY;    SIGMA-MODEL;    SPIN;    ANTIFERROMAGNETS;    STATE;   

DOI  :  10.1103/PhysRevB.43.3790

来源: SCIE

【 摘 要 】

A path-integral approach to the Hubbard model is developed for the whole range of the coupling strength U. At half filling, the strong-coupling results are readily reproduced within the simple Gaussian fluctuations. The low-lying spin wave is shown to be described by the nonlinear sigma-model. The effective coupling of the doped hole with the background fluctuations also agrees with that obtained from the t-J model in the small-doping limit. At finite doping, such a formalism may provide a starting point for investigating the short-range spin-liquid state.

【 授权许可】

Free