Role of spin Hall effect in the topological side surface conduction
- Title
- Role of spin Hall effect in the topological side surface conduction
- Author
- 심상완
- Keywords
- topological insulators; spin relaxation; spin Hall effect; photocurrent; ultrafast
- Issue Date
- 2018-07
- Publisher
- AMER CHEMICAL SOC
- Citation
- ACS PHOTONICS, v. 5, No. 8, Page. 3347-3352
- Abstract
- The nature of spin transport in the bulk and side surface of three-dimensional topological insulator thin film geometry is a relatively unexplored subject, compared to the extensively studied top and bottom surface states. Here we employ time-and space-resolved helicity-dependent photocurrent measurements to investigate the effect of optically excited bulk carriers on the spin-polarized topological side surface conduction. Time-resolved femtosecond double-pulse excitation reveals that the spin current toward the side surface arises from the bulk-originated spin Hall effect (SHE), whose microscopic origin is governed by an Elliott Yafet-type spin relaxation mechanism via an extrinsic side jump process. Bias-and temperature-dependent measurements further confirm that the spin scattering in Bi2Se3 has multiple sources including impurity and electron phonon scattering. The SHE-assisted side surface spin conduction shows an exceptionally high charge-to-spin conversion efficiency of 35% at 77 K, which may offer new spintronic applications of topological insulators such as spin orbit torque or spin-flip controlled light-emitting devices.
- URI
- https://pubs.acs.org/doi/abs/10.1021/acsphotonics.8b00592https://repository.hanyang.ac.kr/handle/20.500.11754/105816
- ISSN
- 2330-4022
- DOI
- 10.1021/acsphotonics.8b00592
- Appears in Collections:
- COLLEGE OF ENGINEERING SCIENCES[E](공학대학) > ELECTRICAL ENGINEERING(전자공학부) > Articles
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