Physical review. B, Condensed matter
Origin of resonating-valence-bond states for a Hubbard-type model
Ken'ichi Takano, Kazuhiro Sano
Abstract
Based on numerical diagonalization of a Hubbard-type model, we propose that, even without exchange interactions, a special kind of hole motion generates a resonating-valence-bond (RVB) state. This hole motion is induced by the second-neighbor transfer in a square lattice. Two types of RVB states appear; one consists only of short singlet pairs and the other includes a small amount of long singlet pairs.