Neutron scatterng in proximate quantum spin liquid alpha-RuCl3

Abstract

The Kitaev quantum spin liquid (KQSL) is an exotic emergent state of matter exhibiting Majorana Fermion and gauge flux excitations. The magnetic insulator α-RuCl3 is thought to realize a proximate KQSL. Here, we use neutron scattering on single crystals of α- RuCl3 to reconstruct dynamical correlations in energy-momentum space. We discover highly unusual signals, including a column of scattering over a large energy interval around the Brillouin zone center which is very stable with temperature. This finding is consistent with scattering from the Majorana excitations of a KQSL. Other, more delicate, experimental features can be transparently associated with perturbations to an ideal model. Our results encourage further study of this prototypical material and may open a window into investigating emergent magnetic Majorana fermions in correlated materials.