Hole Pairs in the Two-Dimensional Hubbard Model

TL;DR

This paper investigates hole interactions in the 2D Hubbard model, revealing effective attraction due to dressed spin polarons, using improved mean field calculations to analyze their kinetic and hopping properties.

Contribution

It introduces a systematic mean field approach to study hole interactions and spin polarons in the Hubbard model, highlighting effective attraction mechanisms.

Findings

Dressed spin polarons exhibit increased kinetic energy and hopping rate.

Effective attraction between holes arises at intermediate couplings.

Method can reproduce known properties of isolated spin polarons.

Abstract

The interactions between holes in the Hubbard model, in the low density, intermediate to strong coupling limit, are investigated. Dressed spin polarons in neighboring sites have an increased kinetic energy and an enhanced hopping rate. Both effects are of the order of the hopping integral and lead to an effective attraction at intermediate couplings. Our results are derived by systematically improving mean field calculations. The method can also be used to derive known properties of isolated spin polarons.