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Frustrated Hubbard ladders and superconductivity in $κ$-BEDT-TTF organic compounds

S. Daul·D. J. Scalapino
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Abstract

Half-filled two-leg Hubbard ladders have spin-gapped short-range antiferromagnetic correlations while three-leg ladders have power law antoferromagnetic correlations, and both systems have d_{x^2-y^2}-power law pairing correlations when they are doped. Thus these ladders exhibit some of the phenomenology seen in the layered cuprates. Here we report results for half-filled frustrated Hubbard ladders, based upon ladder segments taken from a tight-binding model of kappa-BEDT-TTF. Although these ladders are half-filled, varying the degree of frustration can drive them across an insulator-metal transition. We suggest that the spin, charge and pairing correlations of these frustrated ladders near the insulator-metal transition provide support for the notion that kappa-BEDT-TTF is a strongly correlated superconductor.

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S. Daul, D. J. Scalapino. 1999-12-14. Frustrated Hubbard ladders and superconductivity in $κ$-BEDT-TTF organic compounds. https://doi.org/10.1103/physrevb.62.8658

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