Hole pairs in the two-dimensional Hubbard model
Departamento de Física Aplicada, Universidad de Alicante Apartado 99, E-03080 Alicante, Spain
2 Instituto de Ciencia de Materiales de Madrid, CSIC Cantoblanco, E-28049 Madrid, Spain
Accepted: 24 August 1998
The interactions between holes in the Hubbard model, in the low-density, inter mediate-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.
PACS: 74.20.-z – Theories and models of superconducting state / 02.70.Lq – Monte Carlo and statistical methods / 71.10.Fd – Lattice fermion models (Hubbard model, etc.)
© EDP Sciences, 1998