Higher Dimensional Spin Liquid on the Centred Pyrochlore Lattice

Magnetic systems on frustrated lattices have proven a fertile source for the discovery of exotic states of matter, from quantum spin liquids to spin ice. Typically, these frustrated lattices are constructed from triangular or tetrahedral clusters of three or four spins respectively. The metal-azolate framework, [Mn(ta)₂], realizes a centred pyrochlore lattice, where the basic cluster is a centred tetrahedron of five magnetic ions. We study a relevant minimal Heisenberg model, finding a spin liquid in a  large region of the phase diagram. Comparison to measurements of the magnetic properties of [Mn(ta)₂] indicates that the material is proximate to such a state. We propose an effective description of the spin liquid as a three-dimensional slab of a Coulomb phase on a four-dimensional lattice, which rationalizes the low temperature correlations of the model for a large range of parameters. This introduces a novel lattice geometry within which to explore the rich physics of frustrated magnetism.