Origin of Spin-Polarized Photocurrents in the Topological Surface States of Bi2Se3 | Sciact - CRIS-system of Boreskov Institute of Catalysis

Origin of Spin-Polarized Photocurrents in the Topological Surface States of Bi2Se3 Full article

Journal

Physical Review B (started in 2016)
ISSN: 2469-9950 , E-ISSN: 2469-9969

Output data

Year: 2018, Volume: 98, Number: 15, Article number : 155406, Pages count : 7 DOI: 10.1103/physrevb.98.155406

Authors

Ketterl A.S. ¹ , Otto S. ² , Bastian M. ¹ , Andres B. ¹ , Gahl C. ¹ , Minár J. ³ , Ebert H. ⁴ , Braun J. ⁴ , Tereshchenko O.E. ^5,6 , Kokh K.A. ^5,7,8 , Fauster Th. ² , Weinelt M. ¹

Affiliations

1	Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany
2	Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 7, 91058 Erlangen, Germany
3	New Technologies Research Center, West Bohemian University, Univerzitni 8, Plzen, Czech Republic
4	Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
5	Novosibirsk State University, 630090 Novosibirsk, Russian Federation
6	Rzhanov Institute of Semiconductor Physics, 630090 Novosibirsk, Russia
7	Tomsk State University, 634050 Tomsk, Russia
8	Sobolev Institute of Geology and Mineralogy SB RAS, 630090 Novosibirsk, Russia

For the generation of spin-polarized photocurrents in topological insulators, a coupling between photon angular momentum and electron spin is often assumed. Such a coupling seems to be supported by dichroism reported in E(ky )-intensity maps in photoemission. We show in three dimensional two-photon photoemission and one-step photoemission calculations that the circular dichroism is in fact threefold in E(kx , ky) maps although it may appear antisymmetric in E(ky ). The threefold symmetry is inconsistent with the previously assumed coupling between photon momentum and electron’s chiral spin via the orbital momentum. Instead it reflects the surface point group. The only antisymmetric patterns appear in the energy range in which surface and bulk states hybridize. In general, a threefold-symmetric dichroic signal does not support unidirectional photocurrents. Nevertheless, the residual asymmetry of up to 3.5% in our photoemission spectra is compatible with previously observed helicity-dependent photocurrents.

Ketterl A.S. , Otto S. , Bastian M. , Andres B. , Gahl C. , Minár J. , Ebert H. , Braun J. , Tereshchenko O.E. , Kokh K.A. , Fauster T. , Weinelt M.
Origin of Spin-Polarized Photocurrents in the Topological Surface States of Bi2Se3
Physical Review B (started in 2016). 2018. V.98. N15. 155406 :1-7. DOI: 10.1103/physrevb.98.155406 WOS Scopus ANCAN OpenAlex

Submitted:	Feb 7, 2018
Accepted:	Sep 11, 2018
Published print:	Oct 15, 2018

Web of science:	WOS:000446820900006
Scopus:	2-s2.0-85054573045
Chemical Abstracts:	2019:541190
Chemical Abstracts (print):	175:383404
OpenAlex:	W2898045870

DB	Citing
Scopus	16
OpenAlex	16
Web of science	15