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Spin-dependent bandgap renormalization and state-filling effect in Bi2Se3 observed by ultrafast Kerr rotation.
- Source :
-
Applied Physics Letters . 6/3/2024, Vol. 124 Issue 23, p1-6. 6p. - Publication Year :
- 2024
-
Abstract
- We investigate the ultrafast spin dynamics of the prototypical topological insulator Bi2Se3 using time-resolved Kerr rotation (polarization-change) measurements across near-infrared wavelengths. The Kerr rotation angle Δ θ K of Bi2Se3 was found to significantly depend on the photon energy around a resonance transition (∼ 1.0 eV) of bulk states, as well as the ellipticity of the pump light, in the presence of spin excitation. The observed photon-energy dependence of Δ θ K can be well simulated by assuming spin-dependent refractive-index changes in the presence of bandgap renormalization and state-filling effect upon photoexcitation. Our study delivers comprehensive insights into the opto-spintronic properties of bulk Bi2Se3 and the fundamental physical processes underlying polarization changes. These findings are expected to be crucial in developing ultrafast magneto-optical memory devices, which can perform read-and-write operations in the terahertz regime. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00036951
- Volume :
- 124
- Issue :
- 23
- Database :
- Academic Search Index
- Journal :
- Applied Physics Letters
- Publication Type :
- Academic Journal
- Accession number :
- 177745054
- Full Text :
- https://doi.org/10.1063/5.0213640