2026-03-04 京都大学
角度分解光電子分光（ARPES）により観測したバンド分散を示している。
＜関連情報＞
- https://www.kyoto-u.ac.jp/ja/research-news/2026-03-04
- https://www.kyoto-u.ac.jp/sites/default/files/2026-03/web_2503_Yoshida-b5ebc624c517f52f1f7eeed593a9afca.pdf
- https://www.nature.com/articles/s41535-026-00858-8
超高出力因子を有する熱電半金属Ta 2 PdSe 6におけるバンド選択性プラズモニックポーラロン Band-selective plasmonic polaron in thermoelectric semimetal Ta2PdSe6 with ultra-high power factor
Daiki Ootsuki,Akitoshi Nakano,Urara Maruoka,Takumi Hasegawa,Masashi Arita,Miho Kitamura,Koji Horiba,Teppei Yoshida & Ichiro Terasaki
npj Quantum Materials Published:05 February 2026
DOI:https://doi.org/10.1038/s41535-026-00858-8 Unedited version
Abstract
We report the electronic structure of the thermoelectric semimetal Ta2PdSe6 with a large thermoelectric power factor and giant Peltier conductivity by means of angle-resolved photoemission spectroscopy (ARPES). The ARPES spectra reveal the coexistence of a sharp hole band with a light electron mass and a broad electron band with a relatively heavy electron mass, which originate from different quasi-one-dimensional (Q1D) chains in Ta2PdSe6. Moreover, the electron band around the Brillouin-zone (BZ) boundary shows a replica structure with respect to the energy originating from plasmonic polarons due to electron-plasmon interactions. The different scattering effects and interactions in each atomic chain lead to asymmetric transport lifetimes of carriers: a large Seebeck coefficient can be realized even in a semimetal. Our findings pave the way for exploring the thermoelectric materials in previously overlooked semimetals and provide a new platform for low-temperature thermoelectric physics, which has been challenging with semiconductors.
