Fermiology of a topological line-nodal compound CaSb2 and its implication to superconductivity: angle-resolved photoemission study

Chien-Wen Chuang; Seigo Souma; Ayumi Moriya; Kosuke Nakayama; Atsutoshi Ikeda; Mayo Kawaguchi; Keito Obata; Shanta Ranjan Saha; Hidemitsu Takahashi; Shunsaku Kitagawa; Kenji Ishida; Kiyohisa Tanaka; Miho Kitamura; Koji Horiba; Hiroshi Kumigashira; Takashi Takahashi; Shingo Yonezawa; Johnpierre Paglione; Yoshiteru Maeno; Takafumi Sato

doi:10.1103/physrevmaterials.6.104203

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arXiv · 2211.15083

Fermiology of a topological line-nodal compound CaSb2 and its implication to superconductivity: angle-resolved photoemission study

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Abstract

We performed angle-resolved photoemission spectroscopy with micro-focused beam on a topological line-nodal compound CaSb2 which undergoes a superconducting transition at the onset Tc~1.8 K, to clarify the Fermi-surface topology relevant to the occurrence of superconductivity. We found that a three-dimensional hole pocket at the G point is commonly seen for two types of single-crystalline samples fabricated by different growth conditions. On the other hand, the carrier-doping level estimated from the position of the chemical potential was found to be sensitive to the sample fabrication condition. The cylindrical electron pocket at the Y(C) point predicted by the calculations is absent in one of the two samples, despite the fact that both samples commonly show superconductivity with similar Ts's. This suggests a key role of the three-dimensional hole pocket to the occurrence of superconductivity, and further points to an intriguing possibility to control the topological nature of superconductivity by carrier tuning in CaSb2.

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Chien-Wen Chuang, Seigo Souma, Ayumi Moriya, Kosuke Nakayama, Atsutoshi Ikeda, Mayo Kawaguchi, Keito Obata, Shanta Ranjan Saha, Hidemitsu Takahashi, Shunsaku Kitagawa, Kenji Ishida, Kiyohisa Tanaka, Miho Kitamura, Koji Horiba, Hiroshi Kumigashira, Takashi Takahashi, Shingo Yonezawa, Johnpierre Paglione, Yoshiteru Maeno, Takafumi Sato. 2022-11-28. Fermiology of a topological line-nodal compound CaSb2 and its implication to superconductivity: angle-resolved photoemission study. https://doi.org/10.1103/physrevmaterials.6.104203

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