Standard

Origin of spin-polarized photocurrents in the topological surface states of Bi2Se3. / Ketterl, A. S.; Otto, S.; Bastian, M. et al.

In: Physical Review B, Vol. 98, No. 15, 155406, 08.10.2018.

Research output: Contribution to journal › Article › peer-review

Harvard

Ketterl, AS, Otto, S, Bastian, M, Andres, B, Gahl, C, Minár, J, Ebert, H, Braun, J, Tereshchenko, OE, Kokh, KA, Fauster, T & Weinelt, M 2018, 'Origin of spin-polarized photocurrents in the topological surface states of Bi2Se3', Physical Review B, vol. 98, no. 15, 155406. https://doi.org/10.1103/PhysRevB.98.155406

APA

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. (2018). Origin of spin-polarized photocurrents in the topological surface states of Bi2Se3. Physical Review B, 98(15), [155406]. https://doi.org/10.1103/PhysRevB.98.155406

Vancouver

Ketterl AS, Otto S, Bastian M, Andres B, Gahl C, Minár J et al. Origin of spin-polarized photocurrents in the topological surface states of Bi2Se3. Physical Review B. 2018 Oct 8;98(15):155406. doi: 10.1103/PhysRevB.98.155406

Author

Ketterl, A. S. ; Otto, S. ; Bastian, M. et al. / Origin of spin-polarized photocurrents in the topological surface states of Bi2Se3. In: Physical Review B. 2018 ; Vol. 98, No. 15.

BibTeX

@article{8b3558fbca3640f3a403d16275e65a17,
title = "Origin of spin-polarized photocurrents in the topological surface states of Bi2Se3",
abstract = "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.",
keywords = "INSULATORS, CURRENTS, PHASE",
author = "Ketterl, {A. S.} and S. Otto and M. Bastian and B. Andres and C. Gahl and J. Min{\'a}r and H. Ebert and J. Braun and Tereshchenko, {O. E.} and Kokh, {K. A.} and Th Fauster and M. Weinelt",
note = "Publisher Copyright: {\textcopyright} 2018 American Physical Society.",
year = "2018",
month = oct,
day = "8",
doi = "10.1103/PhysRevB.98.155406",
language = "English",
volume = "98",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "15",

}

RIS

TY - JOUR

T1 - Origin of spin-polarized photocurrents in the topological surface states of Bi2Se3

AU - Ketterl, A. S.

AU - Otto, S.

AU - Bastian, M.

AU - Andres, B.

AU - Gahl, C.

AU - Minár, J.

AU - Ebert, H.

AU - Braun, J.

AU - Tereshchenko, O. E.

AU - Kokh, K. A.

AU - Fauster, Th

AU - Weinelt, M.

N1 - Publisher Copyright: © 2018 American Physical Society.

PY - 2018/10/8

Y1 - 2018/10/8

N2 - 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.

AB - 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.

KW - INSULATORS

KW - CURRENTS

KW - PHASE

UR - http://www.scopus.com/inward/record.url?scp=85054573045&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.98.155406

DO - 10.1103/PhysRevB.98.155406

M3 - Article

AN - SCOPUS:85054573045

VL - 98

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 15

M1 - 155406

ER -

ID: 17039392