2020/02/16 by Zheng Zhang, Xiaoli Ma, Jianshu Li +11 · 61 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Charge (physics) #Condensed matter physics #Inelastic neutron scattering #Magnetic and transport properties of perovskites and related materials #Magnetism #Multiferroics and related materials #Neutron #Neutron scattering #Phonon #Physics #Quantum mechanics #Quantum spin liquid #Spin (aerodynamics) #Spin polarization #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.103.035144
published in Physical review. B./Physical review. B 103(3) (American Physical Society) · 7 pages, 4 figures, supplementary material provided, error corrected in Figure 4
arxiv created 2020/02/16 · openalex created_date 2020/02/24 · openalex publication_date 2021/01/27 · arxiv updated 2021/02/03 · openalex updated_date 2026/08/05
By employing inelastic neutron scattering (INS) and Raman scattering (RS) experiments, we comprehensively investigate crystalline electric field (CEF) excitations in NaYbSe2, a new quantum spin liquid candidate that belongs to a large family of triangular-lattice rare-earth chalcogenides with a high-symmetry structure and negligible structural, spin, and charge disordering effects. We can identify CEF excitations at 15.8, 24.3, and 30.5 meV at 5 K. The selected cuts of the INS spectra are well reproduced with a large anisotropy of gab = 2.9 and gc = 1. The CEF excitations are further confirmed by our calculations based on the point charge model. Interestingly, NaYbSe2 exhibits an unusual shift of CEF levels to higher energies with increasing temperatures. Further, the Raman mode close to the first CEF excitation shows an anomalously large softening with decreasing temperatures. The absence of these anomalies in the nonmagnetic isostructural material NaLuSe2 allows us to argue that NaYbSe2 incorporates an unusually strong CEF-phonon resonancelike coupling not reported in any of the triangular-lattice rare-earth chalcogenides. The determination of the CEF excitations suggests the validity of the picture of an effective spin 1/2 at low temperatures.