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Canonical Transformation of the Three-Band Hubbard Model and Hole Pairing

Michele Cini·Gianluca Stefanucci·Adalberto Balzarotti
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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.

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Michele Cini, Gianluca Stefanucci, Adalberto Balzarotti. 1998-10-14. Canonical Transformation of the Three-Band Hubbard Model and Hole Pairing. https://doi.org/10.1016/s0038-1098(98)00566-3

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