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Doped Singlet-Pair Crystal in the Hubbard model on the checkerboard lattice

Didier Poilblanc·Karlo Penc·Nic Shannon
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Abstract

In the limit of large nearest--neighbor and on--site Coulomb repulsions, the Hubbard model on the planar pyrochlore lattice maps, near quarter-filling, onto a doped quantum fully packed loop model. The phase diagram exhibits at quarter filling a novel quantum state of matter, the Resonating Singlet-Pair Crystal, an insulating phase breaking lattice symmetry. Properties of a few doped holes are investigated. In contrast to the doped quantum antiferromagnet, phase separation is restricted to very small hopping leaving an extended``window'' for superconducting pairing. However the later is more fragile for large hopping than in the case of the antiferromagnet.

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Didier Poilblanc, Karlo Penc, Nic Shannon. 2007-04-20. Doped Singlet-Pair Crystal in the Hubbard model on the checkerboard lattice. https://doi.org/10.1103/physrevb.75.220503

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