Ultrafast Momentum-Resolved Hot Electron Dynamics in the Two-Dimensional Topological Insulator Bismuthene
| Autor: | Julian Maklar, Raúl Stühler, Maciej Dendzik, Tommaso Pincelli, Shuo Dong, Samuel Beaulieu, Alexander Neef, Gang Li, Martin Wolf, Ralph Ernstorfer, Ralph Claessen, Laurenz Rettig |
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| Přispěvatelé: | Fritz-Haber-Institut der Max-Planck-Gesellschaft (FHI), Max Planck Society, University of Würzburg, Royal Institute of Technology [Stockholm] (KTH ), Centre d'Etudes Lasers Intenses et Applications (CELIA), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2022 |
| Předmět: |
[PHYS]Physics [physics]
Condensed Matter - Materials Science Condensed Matter - Mesoscale and Nanoscale Physics Mechanical Engineering Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences General Materials Science Bioengineering General Chemistry Condensed Matter Physics |
| Zdroj: | Nano Letters Nano Letters, 2022, 22 (13), pp.5420-5426. ⟨10.1021/acs.nanolett.2c01462⟩ |
| ISSN: | 1530-6992 1530-6984 |
| Popis: | Two-dimensional quantum spin Hall (QSH) insulators are a promising material class for spintronic applications based on topologically-protected spin currents in their edges. Yet, they have not lived up to their technological potential, as experimental realizations are scarce and limited to cryogenic temperatures. These constraints have also severely restricted characterization of their dynamical properties. Here, we report on the electron dynamics of the novel room-temperature QSH candidate bismuthene after photoexcitation using time- and angle-resolved photoemission spectroscopy. We map the transiently occupied conduction band and track the full relaxation pathway of hot photocarriers. Intriguingly, we observe photocarrier lifetimes much shorter than in \red{conventional} semiconductors. This is ascribed to the presence of topological in-gap states already established by local probes. Indeed, we find spectral signatures consistent with these earlier findings. Demonstration of the large band gap and the view into photoelectron dynamics mark a critical step toward optical control of QSH functionalities. Comment: 13 pages, 11 figures |
| Databáze: | OpenAIRE |
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