Ultrafast Spin-to-Charge Conversion at the Surface of Topological Insulator Thin Films
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
| Veröffentlicht in: | Advanced materials (Deerfield Beach, Fla.). - 1998. - 30(2018), 52 vom: 15. Dez., Seite e1802356 |
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| Weitere Verfasser: | , , , , , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2018
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| Zugriff auf das übergeordnete Werk: | Advanced materials (Deerfield Beach, Fla.) |
| Schlagworte: | Journal Article spin-to-charge conversion spintronics surface states terahertz emission spectroscopy topological insulators |
| Zusammenfassung: | © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Strong spin-orbit coupling, resulting in the formation of spin-momentum-locked surface states, endows topological insulators with superior spin-to-charge conversion characteristics, though the dynamics that govern it have remained elusive. Here, an all-optical method is presented, which enables unprecedented tracking of the ultrafast dynamics of spin-to-charge conversion in a prototypical topological insulator Bi2 Se3 /ferromagnetic Co heterostructure, down to the sub-picosecond timescale. Compared to pure Bi2 Se3 or Co, a giant terahertz emission is observed in the heterostructure that originates from spin-to-charge conversion, in which the topological surface states play a crucial role. A 0.12 ps timescale is identified that sets a technological speed limit of spin-to-charge conversion processes in topological insulators. In addition, it is shown that the spin-to-charge conversion efficiency is temperature independent in Bi2 Se3 as expected from the nature of the surface states, paving the way for designing next-generation high-speed optospintronic devices based on topological insulators at room temperature |
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| Beschreibung: | Date Completed 11.01.2019 Date Revised 01.10.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1521-4095 |
| DOI: | 10.1002/adma.201802356 |