Neutron Scattering Signatures of Dipolar-Octupolar Spin Liquids

Dipolar-Octupolar pyrochlores have generated much attention recently due to their capacity to host novel “symmetry enriched” topological phases, while at the same time being described by a relatively simple model Hamiltonian. However, the hybrid nature of the localized magnetic moments in these compounds significantly alters their response to external magnetic fields as well as neutron scattering.

Here, we investigate the latter in detail, focussing on the neutron scattering signatures of different dipolar- and octupolar spin liquid phases. In particular, we take into account all nonzero orders of the magnetic multipole expansion of the local moment, that is we include the dipolar, octupolar, and triakontadipolar contribution.

We show that both octupolar and dipolar spin liquids exhibit highly structured scattering at large momentum transfer, and discuss how single crystal scattering at large momentum transfer can be used to better constrain the nature of candidate spin liquid phases as well as exchange parameters.