2017/08/31 by Min Yong Jeong, Seo Hyoung Chang, Beom Hyun Kim +9
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Atomic orbital #Coupling (piping) #Degeneracy (biology) #Excitation #Ground state #Inelastic neutron scattering #Inelastic scattering #Iron-based superconductors research #Resonant inelastic X-ray scattering #Spin (aerodynamics) #Topological Materials and Phenomena #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1038/s41467-017-00841-9
published as Nature Communications 8, Article number: 782 (2017) · 25 pages, 5 figures + Supplementary Materials [10 pages, 5 figures]
openalex created_date 2017/08/17 · openalex publication_date 2017/09/28 · arxiv created 2017/10/20 · arxiv updated 2017/10/23 · openalex updated_date 2026/08/05
Abstract Strong spin–orbit coupling lifts the degeneracy of t 2g orbitals in 5 d transition-metal systems, leaving a Kramers doublet and quartet with effective angular momentum of J eff = 1/2 and 3/2, respectively. These spin–orbit entangled states can host exotic quantum phases such as topological Mott state, unconventional superconductivity, and quantum spin liquid. The lacunar spinel GaTa 4 Se 8 was theoretically predicted to form the molecular J eff = 3/2 ground state. Experimental verification of its existence is an important first step to exploring the consequences of the J eff = 3/2 state. Here, we report direct experimental evidence of the J eff = 3/2 state in GaTa 4 Se 8 by means of excitation spectra of resonant inelastic X-ray scattering at the Ta L 3 and L 2 edges. We find that the excitations involving the J eff = 1/2 molecular orbital are absent only at the Ta L 2 edge, manifesting the realization of the molecular J eff = 3/2 ground state in GaTa 4 Se 8 .