학술논문
Spin-momentum locking and ultrafast spin-charge conversion in ultrathin epitaxial Bi1-x Sbx topological insulator
Document Type
Conference
Author
Source
2023 48th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 2023 48th International Conference on. :1-2 Sep, 2023
Subject
Language
ISSN
2162-2035
Abstract
We combine spin- and angle-resolved photoemission spectroscopy, and time-resolved THz emission spectroscopy to evidence that spin-charge conversion arises mainly from the surface state in Bi1$_{-x}$Sb x ultrathin films, down to few nanometers where confinement effects emerge. We correlate this large conversion efficiency, typically at the level of the bulk spin Hall effect from heavy metals, to the complex Fermi surface obtained from theoretical calculations of the inverse Rashba-Edelstein response. Both surface state robustness and sizeable conversion efficiency in epitaxial Bi 1-x Sb x thin films bring new perspectives for ultra-low power magnetic random-access memories and broadband THz generation.