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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

<a href="/cs/project/EF15_003%2F0000358" target="_blank" >EF15_003/0000358: Výpočetní a experimentální design pokročilých materiálů s novými funkcionalitami</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review Applied

ISSN

2331-7019

e-ISSN

—

Svazek periodika

21

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

—

Kód UT WoS článku

000731532700001

EID výsledku v databázi Scopus

2-s2.0-85121620618