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arXiv · 1204.2110

Flat-Band Ferromagnetism as a Pauli-Correlated Percolation Problem

M. Maksymenko·A. Honecker·R. Moessner·J. Richter·O. Derzhko
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Abstract

We investigate the location and nature of the para-ferro transition of interacting electrons in dispersionless bands using the example of the Hubbard model on the Tasaki lattice. This case can be analyzed as a geometric site-percolation problem where different configurations appear with nontrivial weights. We provide a complete exact solution for the 1D case and develop a numerical algorithm for the 2D case. In two dimensions the paramagnetic phase persists beyond the uncorrelated percolation point, and the grand-canonical transition is via a first-order jump to an unsaturated ferromagnetic phase.

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M. Maksymenko, A. Honecker, R. Moessner, J. Richter, O. Derzhko. 2012-09-14. Flat-Band Ferromagnetism as a Pauli-Correlated Percolation Problem. https://doi.org/10.1103/physrevlett.109.096404

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