Sterzi, A., Manzoni, G., Sbuelz, L., Cilento, F., Zacchigna, M., Bugnon, Ph, Magrez, A., Berger, H., Crepaldi, A. and Parmigiani, F. (2017). Bulk diffusive relaxation mechanisms in optically excited topological insulators. Phys. Rev. B, 95 (11). COLLEGE PK: AMER PHYSICAL SOC. ISSN 2469-9969
Full text not available from this repository.Abstract
The possibility to inject spin currents in topological insulators (TIs) by ultrashort optical pulses has stimulated intense studies of their out-of-equilibrium electronic properties. However, a comprehensive description of the electronic relaxation dynamics has been elusive, so far. In order to reveal the role of the bulk and surface states in the microscopic scattering mechanisms, we have investigated, by means of time-and angle-resolved photoemission spectroscopy, a wide set of TIs. These have been selected in order to display different positions of the Fermi energy (E-F) within the bulk band structure. When three-dimensional bulk states lie at E-F, we observe a fast relaxation dynamics with a characteristic time scale of a few picoseconds (ps). On the contrary, a long lasting excited state is recorded when only the two-dimensional surface state crosses E-F. These findings suggest the important role played by spatial diffusion in the direction orthogonal to the surface in governing the relaxation mechanisms. We propose that this electron diffusive mechanism is driven by the optically induced temperature gradient that is at play only for electrons residing in bulk states.
| Item Type: | Journal Article | ||||||||||||||||||||||||||||||||||||||||||||
| Creators: |
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| URN: | urn:nbn:de:hbz:38-236285 | ||||||||||||||||||||||||||||||||||||||||||||
| DOI: | 10.1103/PhysRevB.95.115431 | ||||||||||||||||||||||||||||||||||||||||||||
| Journal or Publication Title: | Phys. Rev. B | ||||||||||||||||||||||||||||||||||||||||||||
| Volume: | 95 | ||||||||||||||||||||||||||||||||||||||||||||
| Number: | 11 | ||||||||||||||||||||||||||||||||||||||||||||
| Date: | 2017 | ||||||||||||||||||||||||||||||||||||||||||||
| Publisher: | AMER PHYSICAL SOC | ||||||||||||||||||||||||||||||||||||||||||||
| Place of Publication: | COLLEGE PK | ||||||||||||||||||||||||||||||||||||||||||||
| ISSN: | 2469-9969 | ||||||||||||||||||||||||||||||||||||||||||||
| Language: | English | ||||||||||||||||||||||||||||||||||||||||||||
| Faculty: | Unspecified | ||||||||||||||||||||||||||||||||||||||||||||
| Divisions: | Unspecified | ||||||||||||||||||||||||||||||||||||||||||||
| Subjects: | no entry | ||||||||||||||||||||||||||||||||||||||||||||
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| Refereed: | Yes | ||||||||||||||||||||||||||||||||||||||||||||
| URI: | http://kups.ub.uni-koeln.de/id/eprint/23628 |
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