A quantum dimer model for the pseudogap metal

We propose a quantum dimer model for the metallic state of the hole-doped cuprates at low hole density, $p$. The Hilbert space is spanned by spinless, neutral, bosonic dimers and spin $S=1\mathrm{/}2$, charge $+e$ fermionic dimers. The model realizes a `fractionalized Fermi liquid’ with no symmetry-breaking and small hole pocket Fermi surfaces enclosing a total area determined by $p$. Exact diagonalization, on lattices of sizes up to $8\times 8$, shows anisotropic quasiparticle residue around the pocket Fermi surfaces. We discuss the relationship to experiments.