Hubbard Model on the Pyrochlore Lattice: a 3D Quantum Spin Liquid

TL;DR

This paper shows that the Hubbard model on the pyrochlore lattice can host a three-dimensional quantum spin liquid phase with deconfined spinons and spin-charge separation, relevant for real materials.

Contribution

It identifies a novel quantum spin-liquid phase in the Hubbard model on the pyrochlore lattice, expanding understanding of 3D spin liquids in realistic systems.

Findings

Existence of an extended quantum spin-liquid phase in the Hubbard model on the pyrochlore lattice

Presence of deconfined, massive spinon excitations

Spin-charge separation upon doping in the spin-liquid state

Abstract

We demonstrate that the insulating one-band Hubbard model on the pyrochlore lattice contains, for realistic parameters, an extended quantum spin-liquid phase. This is a three-dimensional spin liquid formed from a highly degenerate manifold of dimer-based states, which is a subset of the classical dimer coverings obeying the ice rules. It possesses spinon excitations, which are both massive and deconfined, and on doping it exhibits spin-charge separation. We discuss the realization of this state in effective S = 1/2 pyrochlore materials with and without spin-orbit coupling.