Site-selective 11B NMR studies on YbAlB4

TMU International Symposium on "New Quantum Phases Emerging from Novel Crystal Structure"

Takano, S.^1 ; Grbic, M.S.^1 ; Kimura, K.^1 ; Yoshida, M.^1 ; Takigawa, M.^1 ; Farrell, E.C.T.O.^1 ; Kuga, K.^1 ; Nakatsuji, S.^1 ; Harima, H.^2

Institute for Solid State Physics, University of Tokyo, Kashiwa

277-8581, Japan^1

Graduate School of Science, Kobe University, Kobe

657-8501, Japan^2

关键词: Ab initio calculations;    Conduction electrons;    Crystallographic sites;    Electric field gradients;    Intermediate valence;    Isostructural polymorphs;    Quantum criticality;    Radial patterns;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/683/1/012008/pdf
DOI  :  10.1088/1742-6596/683/1/012008

来源: IOP

【 摘 要 】

β-YbAlB4is a distinctive heavy fermion superconductor that exhibits unconventional quantum criticality without tuning in a strongly intermediate valence state. In this paper, we report the result of11B NMR measurements on the single crystals of, β-YbAlB4and α- YbAlB4, the locally isostructural polymorph of β-YbAlB4. All11B NMR lines for both samples were successfully assigned to inequivalent crystallographic sites by comparing the experimental results and the ab-initio calculation of the electric field gradient. In both compounds, the anisotropy of the Knight shift exhibits a characteristic radial pattern, indicating approximate axial symmetry of the hybridization between the Yb-4f electrons and the conduction electrons.