Spin slush in an extended spin ice model

TL;DR

The paper introduces 'spin slush', a novel classical spin liquid on the pyrochlore lattice with heterogeneous dynamics and extended ice states, revealing complex ground state structures and potential material applications.

Contribution

It presents a new spin liquid state called 'spin slush' arising from extended interactions in spin ice, with unique dynamical heterogeneity and complex ground state manifold.

Findings

Exhibits extremely slow relaxation for some spins and rapid fluctuations for others.

Features extended ground state manifold with branching structures including various defect types.

Displays liquid-like spin correlation patterns indicating intermediate range order.

Abstract

We introduce a new classical spin liquid on the pyrochlore lattice by extending spin ice with further neighbour interactions. We find that this disorder free spin model exhibits a form of dynamical heterogeneity with extremely slow relaxation for some spins while others fluctuate quickly down to zero temperature. We thus call this state "spin slush", in analogy to the heterogeneous mixture of solid and liquid water. This behaviour is driven by the structure of the ground state manifold which extends the celebrated the two-in/two-out ice states to include branching structures built from three-in/one-out, three-out/one-in and all-in/all-out tetrahedra defects. Distinctive liquid-like patterns in the spin correlations serve as a signature of this intermediate range order. Possible applications to materials as well the effects of quantum tunneling are discussed.