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arXiv · 2004.06315

Hard and soft x-ray photoemission spectroscopy study of the new Kondo system SmO thin film

Shoya Sakamoto·Kenichi Kaminaga·Daichi Oka·Ryu Yukawa·Masafumi Horio·Yuichi Yokoyama·Kohei Yamamoto·Kou Takubo·Yosuke Nonaka·Keisuke Koshiishi·Masaki Kobayashi·Arata Tanaka·Akira Yasui·Eiji Ikenaga·Hiroki Wadati·Hiroshi Kumigashira·Tomoteru Fukumura·Atsushi Fujimori
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Abstract

SmO thin film is a new Kondo system showing a resistivity upturn around 10 K and was theoretically proposed to have a topologically nontrivial band structure. We have performed hard x-ray and soft x-ray photoemission spectroscopy to elucidate the electronic structure of SmO. From the Sm 3$d$ core-level spectra, we have estimated the valence of Sm to be $\sim$2.96, proving that the Sm has a mixed valence. The valence-band photoemission spectra exhibit a clear Fermi edge originating from the Sm 5$d$-derived band. The present finding is consistent with the theory suggesting a possible topological state in SmO and show that rare-earth monoxides or their heterostructures can be a new playground for the interplay of strong electron correlation and spin-orbit coupling.

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Shoya Sakamoto, Kenichi Kaminaga, Daichi Oka, Ryu Yukawa, Masafumi Horio, Yuichi Yokoyama, Kohei Yamamoto, Kou Takubo, Yosuke Nonaka, Keisuke Koshiishi, Masaki Kobayashi, Arata Tanaka, Akira Yasui, Eiji Ikenaga, Hiroki Wadati, Hiroshi Kumigashira, Tomoteru Fukumura, Atsushi Fujimori. 2020-04-14. Hard and soft x-ray photoemission spectroscopy study of the new Kondo system SmO thin film. https://doi.org/10.1103/physrevmaterials.4.095001

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