Absence of hole pairing in a simple t-J model on the Shastry-Sutherland lattice

Abstract

The Shastry-Sutherland model is a two-dimensional frustrated spin model whose ground state is a spin gap state. We study this model doped with one and two holes on a 32-site lattice using exact diagonalization. When t'>0, we find that the diagonal dimer order that exists at half-filling are retained at these moderate doping levels. No other order is found to be favored on doping. The holes are strongly repulsive unless the hopping terms are unrealistically small. Therefore, the existence of a spin gap at half-filling does not guarantee hole-pairing in the present case.

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Cited by in corpus (10)

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• Mott transition and Antiferromagnetic Metal on Shastry-Sutherland Lattice
• Doped Valence Bond Solid and Superconductivity on the Shastry-Sutherland Lattice
• Supersolid phases of a doped valence-bond quantum antiferromagnet: Evidence for a coexisting superconducting order parameter
• Spin-polaron excitations in a doped Shastry-Sutherland model
• In-plane substitution effect on the magnetic properties of two-dimensional Spin-gap system SrCu${}_2$(BO${}_3$)${}_2$
• Shaping Magnetic Order by Local Frustration for Itinerant Fermions on a Graph
• Insulator-metal transition and quasi-flat-band of Shastry-Sutherland lattice
• Antiferromagnetism and singlet formation in underdoped high-Tc cuprates: Implications for superconducting pairing