2017/02/16 by Kejing Ran, Jinghui Wang, Wei Wang +15 · 230 citations
Engineering · Physics and Astronomy · #Advanced Condensed Matter Physics #Anisotropy #Antiferromagnetism #Brillouin zone #Condensed matter physics #Coupling (piping) #Ferromagnetism #Inelastic neutron scattering #Isotropy #Materials science #Neutron scattering #Perovskite Materials and Applications #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Scattering #Spin (aerodynamics) #Spin wave #Thermodynamics #cond-mat.mtrl-sci #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.118.107203
published in Physical Review Letters 118(10), 107203 (American Physical Society) · To appear in PRL
arxiv created 2017/02/16 · openalex created_date 2017/03/03 · openalex publication_date 2017/03/07 · arxiv updated 2017/03/30 · openalex updated_date 2026/08/05
Kitaev interactions underlying a quantum spin liquid have long been sought, but experimental data from which their strengths can be determined directly, are still lacking. Here, by carrying out inelastic neutron scattering measurements on high-quality single crystals of \ensuremathα\text\ensuremath-RuCl3, we observe spin-wave spectra with a gap of \ensuremath∼2 meV around the M point of the two-dimensional Brillouin zone. We derive an effective-spin model in the strong-coupling limit based on energy bands obtained from first-principles calculations, and find that the anisotropic Kitaev interaction K term and the isotropic antiferromagnetic off-diagonal exchange interaction \mathrm\ensuremathΓ term are significantly larger than the Heisenberg exchange coupling J term. Our experimental data can be well fit using an effective-spin model with K=\ensuremath-6.8 meV and \mathrm\ensuremathΓ=9.5 meV. These results demonstrate explicitly that Kitaev physics is realized in real materials.