Abstract
We discuss an electronic model consisting of two planes, each described by a t — J model, coupled by an antiferromagnetic interaction J′ between planes. For J′≥ J we show the presence of a spin-gap in the spectrum and hole-pair formation upon doping. The model superconducts away from half-filling. We support our claims by numerical studies of binding energy of holes and pairing correlations on finite clusters. The pairing operator is an s — wave spin-singlet with one member of the pair in each plane. Although all interactions are explicitly repulsive, our model belongs to the universality class of the U < 0 Hubbard model with |U| ≫ t. We argue that this model can be physically realized in the two Cu-O layers of the unit cell of YBa2Cu3O6+x and also in the orthorhombic compound (VO)2P2O7.
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Dagotto, E. (1992). S-Wave Superconductivity in the t — J Model with Two Planes. In: Miyashita, S., Imada, M., Takayama, H. (eds) Computational Approaches in Condensed-Matter Physics. Springer Proceedings in Physics, vol 70. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-84821-6_13
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DOI: https://doi.org/10.1007/978-3-642-84821-6_13
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