Hole-hole superconducting pairing in the t-J model induced by long-range spin-wave exchange

✍ Scribed by V.V Flambaum; M.Yu Kuchiev; O.P Sushkov

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 856 KB
• Volume: 227
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)90081-7

✦ Synopsis

Long-range (r ~ p ~-~ >> lattice spacing) spin-wave exchange produces a very strong pairing of the holes. Solutions of the BCStype equation for the superconducting gap A are found for various symmetries. The strongest pairing corresponds to d wave symmetry. The physical reasons for the strong pairing are: ( 1 ) the typical spin-wave energy is higher than the Fermi energy, (2) a "collapse" effect in the attractive potential ( -1/r 2) describing the interaction between two holes and (3) the hole dispersion is strongly asymmetric. At hole concentrations ~~ 0.01-0.3 we get A ~ Tc ~ Ee. At very low concentration of the holes the manybody wave function of the ground state decays into a product of two-hole bound states.