HOLE SPECTRUM IN THE 2-DIMENSIONAL HUBBARD-MODEL

We propose a variational scheme to describe the single hole spectrum in the framework of the conventional Hubbard mode. Strictly speaking, we deal with its version well-known as the t-J model. The single hole wave function should display nonperturbative antiferromagnetic (AFM) ordering far from a hole and rearrangement of spins surrounding a hole inside the region of a linear size R ∝ (t/J) 1 4. Different trial functions describing an AFM background are taken to investigate the hole spectrum. For the backgrounds which are characterized by quantum spin fluctuations the bottom of the hole band is situated close to the boundary line of the Brillouin magnetic cell. Dispersion along the boundary is small as compared to the whole band width. © 1990.