Croes Boris, Llopez Alexandre, Tagne-Kaegom Calvin, Tegomo-Chiogo Bodry, Kierren Bertrand, Müller Pierre, Curiotto Stefano, Le Fèvre Patrick, Bertran François, Saúl Andrés, Fagot-Revurat Yannick, Leroy Frédéric, Cheynis Fabien
Aix Marseille Univ, CNRS, CINAM, AMUtech, 13288 Marseille, France.
Institut Jean Lamour, UMR 7198, CNRS-Université de Lorraine, Campus ARTEM, 2 Allée André Guinier, BP 50840, 54011 Nancy, France.
Nano Lett. 2024 Oct 23;24(42):13224-13231. doi: 10.1021/acs.nanolett.4c03281. Epub 2024 Oct 14.
Ferroelectric Rashba semiconductors (FERSCs) such as α-GeTe are promising candidates for energy-efficient information technologies exploiting spin-orbit coupling (SOC) and are termed spin-orbitronics. In this work, the thickness limit of the Rashba-SOC effect in α-GeTe films is investigated. We demonstrate, using angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations performed on pristine GeTe, that down to 1 nm, GeTe(111) films on a Sb-covered Si(111) substrate continuously exhibit a giant Rashba effect characterized, at 1 nm, by a constant of 5.2 ± 0.5 eV·Å. X-ray photoemission spectroscopy (XPS) allows the understanding of the persistence of the Rashba effect by evidencing a compensation of Ge vacancy defects resulting from the insertion of Sb interfacial atoms in the early stage growth of the GeTe(111) films.
诸如α - GeTe之类的铁电 Rashba 半导体（FERSCs）是利用自旋轨道耦合（SOC）的节能信息技术的有前途的候选材料，被称为自旋轨道电子学。在这项工作中，研究了α - GeTe 薄膜中 Rashba - SOC 效应的厚度极限。我们使用角分辨光电子能谱（ARPES）以及对原始 GeTe 进行的第一性原理计算表明，如果在覆盖有 Sb 的 Si(111) 衬底上生长 GeTe(111) 薄膜，即使薄膜厚度低至 1 nm，也会持续呈现巨大的 Rashba 效应，在 1 nm 时，其常数为 5.2 ± 0.5 eV·Å。X 射线光电子能谱（XPS）通过证明在 GeTe(111) 薄膜生长早期插入 Sb 界面原子导致的 Ge 空位缺陷得到补偿，从而有助于理解 Rashba 效应的持续性。
