One-Particle Spectral Weightof the Two-Dimensional Hubbard Modelin the t-Matrix Approximation

Abstract

The one-particle spectral weight of the two-dimensional Hubbard model is studied in the t-matrix approximation. A single quasi-particle peak is obtained in the spectrum so that the quasi-particle picture holds in the t-matrix approximation, while in the second-order perturbation (H. Fukuyama and M. Ogata: J. Phys. Soc. Jpn. 63 (1994) 3923) it is concluded that splitting of the spectral weight occurs.