We propose a canonical tranformation approach to the effective interaction W-eff between two holes, based on the three-band Hubbard model but ready to include extra interactions as well. An effective two-body Hamiltonian can in principle be obtained including any kind of virtual intermediate states. We derive the closed-form analytic expression of the effective interaction including 4-body virtual states, describing the exchange of an electron-hole pair to all orders. The resulting integral equation, valid for the full plane, leads to a Cooper-like instability of the Fermi liquid. The two-hole bound states generalize those reported earlier in cluster calculations by exact diagonalisation methods. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.
Cini, M., Stefanucci, G., Balzarotti, A. (1998). Canonical transformation of the three-band Hubbard model and hole pairing. SOLID STATE COMMUNICATIONS, 109(4), 229-233.
Canonical transformation of the three-band Hubbard model and hole pairing
CINI, MICHELE;STEFANUCCI, GIANLUCA;BALZAROTTI, ADALBERTO
1998-01-01
Abstract
We propose a canonical tranformation approach to the effective interaction W-eff between two holes, based on the three-band Hubbard model but ready to include extra interactions as well. An effective two-body Hamiltonian can in principle be obtained including any kind of virtual intermediate states. We derive the closed-form analytic expression of the effective interaction including 4-body virtual states, describing the exchange of an electron-hole pair to all orders. The resulting integral equation, valid for the full plane, leads to a Cooper-like instability of the Fermi liquid. The two-hole bound states generalize those reported earlier in cluster calculations by exact diagonalisation methods. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
