Neutron scattering in the proximate quantum spin liquid α-RuCl ₃

TLDR

Quantum spin liquids are materials whose magnetic spins remain disordered even at absolute zero, a phenomenon that has long intrigued physicists. The study aims to identify a material that realizes the Kitaev spin model, a honeycomb lattice hosting Majorana fermion excitations. The authors performed a comprehensive inelastic neutron‑scattering investigation on single crystals of α‑RuCl₃, a candidate Kitaev spin liquid. The energy, momentum, and temperature dependence of the scattering data aligns with predictions of the Kitaev model. Published in Science (p.

Abstract

Sighting of magnetic Majorana fermions? Quantum spin liquids—materials whose magnetic spins do not settle into order even at absolute zero temperature—have long captured the interest of physicists. A particularly lofty goal is finding a material that can be described by the so-called Kitaev spin model, a network of spins on a honeycomb lattice that harbors Majorana fermions as its excitations. Banerjee et al. present a comprehensive inelastic neutron scattering study of single crystals of the material α-RuCl 3 , which has been predicted to a host a Kitaev spin liquid. The unusual dependence of the data on energy, momentum, and temperature is consistent with the Kitaev model. Science , this issue p. 1055