Presentation Information
[3E11]Surface termination dependence of the electronic structure in CeCoIn5 measured with micro-ARPES
*Kaito Nishihara1, Takuto Nakamura2,1, Yoshiyuki Ohtsubo3, Reo Miyagawa1, Ryosuke Koizumi4, Teppei Takahashi4, Makoto Yokoyama4, Ken-ichi Ozawa5, Shin-ichi Kimura2,1,6 (1. Graduate School of Science, Osaka University, 2. Graduate School of Frontier Biosciences, Osaka University, 3. National Institutes for Quantum Science and Technology, 4. Graduate School of Science, Ibaraki University, 5. High Energy Accelerator Research Organization, 6. Institute for Molecular Science)
To investigate the termination effect on the surface electronic structure of heavy fermion materials, we measured micro-ARPES on the cleaved surface of a typical heavy fermion superconductor, CeCoIn5, and classified the ARPES spectra into four groups, which have different intensities of the hybridization between the conduction (c) and 4f electrons, namely c-f hybridization, using a machine-learning technique. The ARPES spectra with the strong c-f hybridization have a positive correlation to the Co 3d peak intensity, suggesting the Co-terminated surface and bulk-like character of Ce ions. On the other hand, the weak c-f hybridized ARPES spectra with the weak Co 3d peak intensity are suggested to correspond to the Ce-In-terminated surface, where Ce ions appear on the surface. These results suggest that the number of ligands affects the surface electronic structure.