Optimal inhomogeneity for pairing in Hubbard systems with next-nearest-neighbor hopping
| Autor: | Wachtel, Gideon, Baruch, Shirit, Orgad, Dror |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 96, 064527 (2017) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.96.064527 |
| Popis: | Previous studies have shown that bipartite Hubbard systems with inhomogeneous hopping amplitudes can exhibit higher pair-binding energies than the uniform model. Here we examine whether this result holds for systems with a more generic band structure. To this end, we use exact diagonalization and the density matrix renormalization group method to study the 4x4 Hubbard cluster and the two-leg Hubbard ladder with checkerboard-modulated nearest-neighbor hopping, t, and next-nearest-neighbor (diagonal) hopping, t_d. We find that the strongest pairing continues to occur at an intermediate level of inhomogeneity. While the maximal pair-binding energy is enhanced by a positive t_d/t, it is suppressed and appears at weaker repulsion strengths and smaller hole concentrations when t_d/t is negative. We point out a possible connection between the pairing maximum and the magnetic properties of the system. Comment: 6 pages, 8 figures |
| Databáze: | arXiv |
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