Emergence and characterization of attraction in a dynamic Hubbard model

The Dynamic Hubbard Model (DHM) has been introduced as a framework for the electron-hole asymmetry observed in materials like high-temperature superconductors. In this study, we aim to understand the intricate dynamics of hole interactions, particularly focusing on the competition between on-site repulsion and hole-lattice coupling. Our results reveal a striking feature-an effective nearest-neighbor attraction between holes, even in the presence of the on-site repulsion typical of Mott insulators. Notably, the on-site repulsion not only coexists but also enhances the nearest-neighbor coupling. Our exploration of the DHM unravels unexpected and significant characteristics, enriching our understanding of hole interactions in correlated electron systems. The model's capacity to capture both on-site repulsion and effective nearest-neighbor attraction offers a valuable perspective.