Magnetic correlations and pairing in the 1/5-depleted square lattice Hubbard model

Abstract

We study the single-orbital Hubbard model on the 1/5-depleted square lattice geometry, which arises in such diverse systems as the spin-gap magnetic insulator CaV4O9 and ordered-vacancy iron selenides, presenting new issues regarding the origin of both magnetic ordering and superconductivity in these materials. We find a rich phase diagram that includes a plaquette singlet phase, a dimer singlet phase, a Neel and a block-spin antiferromagnetic phase, and stripe phases. Quantum Monte Carlo simulations show that the dominant pairing correlations at half filling change character from d-wave in the plaquette phase to extended s-wave upon transition to the Neel phase. These findings have intriguing connections to iron-based superconductors, and suggest that some physics of multiorbital systems can be captured by a single-orbital model at different dopings.

8 pages, 8 figures

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Cited by in corpus (6)

• Geometry Dependence of the Sign Problem
• Design of altermagnetic models from spin clusters
• Direct observation of fragile Mott insulators on plaquette Hubbard lattices
• Magnetic phase diagram and Mott transition of the half-filled 1/5-depleted Hubbard model with frustration
• Magnetic Order-Disorder Transitions on a 1/3 - Depleted Square Lattice
• Site-selective correlations in interacting "flat-band" quasicrystals