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.
