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Charge degrees in the quarter-filled checkerboard lattice

F. Pollmann·J. J. Betouras·E. Runge·P. Fulde
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Abstract

For a systematic study of charge degrees of freedom in lattices with geometric frustration, we consider spinless fermions on the checkerboard lattice with nearest-neighbor hopping $t$ and nearest-neighbor repulsion $V$ at quarter-filling. An effective Hamiltonian for the limit $|t|\ll V$ is given to lowest non-vanishing order by the ring exchange ($\sim t^{3}/V^{2}$). We show that the system can equivalently be described by hard-core bosons and map the model to a confining U(1) lattice gauge theory.

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F. Pollmann, J. J. Betouras, E. Runge, P. Fulde. 2007-12-03. Charge degrees in the quarter-filled checkerboard lattice. https://doi.org/10.1016/j.jmmm.2006.10.348

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