2025-12-11 理化学研究所,東京大学,高エネルギー加速器研究機構
整数比の格子整合と歪（ひず）みが抑制された薄膜における超伝導の発現
＜関連情報＞
- https://www.riken.jp/press/2025/20251211_1/index.html
- https://www.nature.com/articles/s41467-025-65902-w
高次エピタキシーにより実現したFeTe薄膜の超伝導と単斜晶系歪みの抑制 Superconductivity and suppressed monoclinic distortion in FeTe films enabled by higher-order epitaxy
Yuki Sato,Soma Nagahama,Shunsuke Kitou,Hajime Sagayama,Ilya Belopolski,Ryutaro Yoshimi,Minoru Kawamura,Atsushi Tsukazaki,Naoya Kanazawa,Takuya Nomoto,Ryotaro Arita,Taka-hisa Arima,Masashi Kawasaki & Yoshinori Tokura
Nature Communications Published:05 December 2025
DOI:https://doi.org/10.1038/s41467-025-65902-w
Abstract
Molecular beam epitaxy enables the growth of thin film materials with novel properties and functionalities. Typically, the lattice constants of films and substrates are designed to match to minimise disorders and strains. However, significant lattice mismatches can result in higher-order epitaxy, where commensurate growth occurs with a period defined by integer multiples of the lattice constants. Despite its potential, higher-order epitaxy is rarely used to enhance material properties or induce emergent phenomena. Here, we report single-crystalline FeTe films grown via 6:5 commensurate higher-order epitaxy on CdTe(001) substrates. Scanning transmission electron microscopy reveals self-organised periodic interstitials near the interface, arising from higher-order lattice matching. Synchrotron x-ray diffraction shows that the tetragonal-to-monoclinic structural transition in bulk FeTe is strongly suppressed. Remarkably, these films exhibit substrate-selective two-dimensional superconductivity, likely due to suppressed monoclinic distortion. These findings demonstrate the potential of higher-order epitaxy as a tool to control materials and inducing emergent phenomena.
