Document Type

Article

Publication Date

September 2014

Publication Title

Physical Review Letters

Volume

113

Issue Number

10

First Page

106402

DOI

10.1103/PhysRevLett.113.106402

Keywords

Correlations, Pairing, Magnetic, Hubbard, Model, Lattice

Disciplines

Atomic, Molecular and Optical Physics | Physical Sciences and Mathematics | Physics

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 Néel 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 Néel 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.

Comments

© 2014 American Institute of Physics DOI:10.1103/PhysRevLett.113.106402

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