論文 Optical conductivity and band gap in the double-Weyl candidate SrSi 2 at ambient pressure

L. Z. Maulana ORCID ; A. A. Tsirlin ORCID ; E. Uykur ORCID ; Y. Saito ORCID ; M. Dressel ORCID ; M. Imai SAMURAI ORCID ; A. V. Pronin ORCID

コレクション

引用
L. Z. Maulana, A. A. Tsirlin, E. Uykur, Y. Saito, M. Dressel, M. Imai, A. V. Pronin. Optical conductivity and band gap in the double-Weyl candidate SrSi 2 at ambient pressure. Physical Review B. 2025, 112 (15), 155209. https://doi.org/10.1103/y1gj-67wz

説明:

(abstract)

We probe the possible double-Weyl state in cubic SrSi2 using optical spectroscopy. The complex optical conductivity was measured in a frequency range from 70 cm−1 to 22 000 cm−1 at temperatures down to 10 K at ambient pressure. The optical response of SrSi2 can be well separated into the intraband (free carriers) and interband contributions. Additionally, four infrared-active phonons are detected. As follows from the optical spectra, the free-carrier density decreases with decreasing temperature, consistent with an activation behaviour. Experimental interband conductivity juxtaposed with ab initio calculations shows that conventional density-functional theory fails to describe the electronic structure of SrSi2 in the vicinity of the Fermi level. A semi-local exchange-correlation potential allows a much better agreement with the experiment, resulting in the trivial (gapped) band structure of SrSi2. The direct gap estimated from the measurements is approximately 40 meV.

権利情報:

キーワード: silicide, semiconductor, optical conductivity

刊行年月日: 2025-10-20

出版者: American Physical Society (APS)

掲載誌:

  • Physical Review B (ISSN: 24699950) vol. 112 issue. 15 155209

研究助成金:

  • Deutsche Forschungsgemeinschaft DR228/51-3
  • Japan Society for the Promotion of Science JP22H00268

原稿種別: 著者最終稿 (Accepted manuscript)

MDR DOI: https://doi.org/10.48505/nims.5822

公開URL: https://doi.org/10.1103/y1gj-67wz

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更新時刻: 2025-10-24 08:30:08 +0900

MDRでの公開時刻: 2025-10-24 08:18:41 +0900

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ファイル名 SrSi2.pdf (サムネイル)
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