Superlinear Photogalvanic Effects in (Bi0.3Sb0.7)2(Te0.1Se0.9)3: Probing Three-Dimensional Topological Insulator Surface States at Room Temperature

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23640%2F21%3A43964069" target="_blank" >RIV/49777513:23640/21:43964069 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1103/PhysRevApplied.16.064030" target="_blank" >https://doi.org/10.1103/PhysRevApplied.16.064030</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1103/PhysRevApplied.16.064030" target="_blank" >10.1103/PhysRevApplied.16.064030</a>

Result language
angličtina
Original language name
Superlinear Photogalvanic Effects in (Bi0.3Sb0.7)2(Te0.1Se0.9)3: Probing Three-Dimensional Topological Insulator Surface States at Room Temperature
Original language description
We report on the observation of a complex nonlinear intensity dependence of the circular and linear photogalvanic currents induced by infrared radiation in compensated (Bi0.3Sb0.7)(2) (Te0.1Se0.9)(3) three-dimensional topological insulators. The photocurrents are induced by direct optical transitions between topological surface and bulk states. We show that an increase in the radiation intensity results first in a highly superlinear rise in the amplitude of both types of photocurrents, whereas at higher intensities the photocurrent saturates. Our analysis of the observed nonlinearities shows that the superlinear behavior of the photocurrents is caused by heating of the electron gas, while the saturation is induced by slow relaxation of the photoexcited carriers, resulting in absorbance bleaching. The observed nonlinearities give access to the Fermi-level position with respect to the Dirac point and the energy relaxation times of Dirac fermions, providing an experimental room-temperature probe of topological surface states.
Czech name
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Czech description
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Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project
<a href="/en/project/EF15_003%2F0000358" target="_blank" >EF15_003/0000358: Computational and Experimental Design of Advanced Materials with New Functionalities</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year
2021
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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