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The anisotropic quantum antiferromagnet on the Sierpinski gasket: Ground state and thermodynamics

Andreas Voigt·Wolfgang Wenzel·Johannes Richter·Piotr Tomczak
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Abstract

We investigate an antiferromagnetic s=1/2 quantum spin system with anisotropic spin exchange on a fractal lattice, the Sierpinski gasket. We introduce a novel approximative numerical method, the configuration selective diagonalization (CSD) and apply this method to the Sierpinski gasket with N=42. Using this and other methods we calculate ground state energies, spin gap, spin-spin correlations and specific heat data and conclude that the s=1/2 quantum antiferromagnet on the Sierpinski gasket shows a disordered magnetic ground state with a very short correlation length of about 1 and an, albeit very small, spin gap. This conclusion holds for Heisenberg as well a for XY exchange.

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Andreas Voigt, Wolfgang Wenzel, Johannes Richter, Piotr Tomczak. 2004-03-04. The anisotropic quantum antiferromagnet on the Sierpinski gasket: Ground state and thermodynamics. https://doi.org/10.1140/epjb%2Fe2004-00098-8

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