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Plaquette bond order wave in the quarter-filled extended Hubbard model on the checkerboard lattice

Martin Indergand·Carsten Honerkamp·Andreas Laeuchli·Didier Poilblanc·Manfred Sigrist
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Abstract

An extended Hubbard model (including nearest-neighbor repulsion and antiferromagnetic spin exchange) is investigated on the frustrated checkerboard lattice, a two-dimensional analog of the pyrochlore lattice. Combining Gutzwiller renormalized mean-field (MF) calculations, exact diagonalization (ED) techniques, and a weak-coupling renormalization group (RG) analysis we provide strong evidence for a crystalline valence bond plaquette phase at quarter-filling. The ground state is twofold degenerate and breaks translation symmetry. The bond energies show a staggering while the charge distribution remains uniform.

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Martin Indergand, Carsten Honerkamp, Andreas Laeuchli, Didier Poilblanc, Manfred Sigrist. 2007-01-22. Plaquette bond order wave in the quarter-filled extended Hubbard model on the checkerboard lattice. https://doi.org/10.1103/physrevb.75.045105

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