Deutsch
 
Benutzerhandbuch Datenschutzhinweis Impressum Kontakt
  DetailsucheBrowse

Datensatz

DATENSATZ AKTIONENEXPORT

Freigegeben

Zeitschriftenartikel

Ultrafast photocurrents at the surface of the three-dimensional topological insulator Bi2Se3

MPG-Autoren
/persons/resource/persons39361

Braun,  Lukas
Physical Chemistry, Fritz Haber Institute, Max Planck Society;

/persons/resource/persons22250

Wolf,  Martin
Physical Chemistry, Fritz Haber Institute, Max Planck Society;

/persons/resource/persons21693

Kampfrath,  Tobias
Physical Chemistry, Fritz Haber Institute, Max Planck Society;

Externe Ressourcen
Es sind keine Externen Ressourcen verfügbar
Volltexte (frei zugänglich)

ncomms13259.pdf
(Verlagsversion), 555KB

Ergänzendes Material (frei zugänglich)
Es sind keine frei zugänglichen Ergänzenden Materialien verfügbar
Zitation

Braun, L., Mussler, G., Hruban, A., Konczykowski, M., Schumann, T., Wolf, M., et al. (2016). Ultrafast photocurrents at the surface of the three-dimensional topological insulator Bi2Se3. Nature Communications, 7: 13259. doi:10.1038/ncomms13259.


Zitierlink: http://hdl.handle.net/11858/00-001M-0000-002C-16B9-6
Zusammenfassung
Three-dimensional topological insulators are fascinating materials with insulating bulk yet metallic surfaces that host highly mobile charge carriers with locked spin and momentum. Remarkably, surface currents with tunable direction and magnitude can be launched with tailored light beams. To better understand the underlying mechanisms, the current dynamics need to be resolved on the timescale of elementary scattering events (∼10 fs). Here, we excite and measure photocurrents in the model topological insulator Bi2Se3 with a time resolution of 20 fs by sampling the concomitantly emitted broadband terahertz (THz) electromagnetic field from 0.3 to 40 THz. Strikingly, the surface current response is dominated by an ultrafast charge transfer along the Se–Bi bonds. In contrast, photon-helicity-dependent photocurrents are found to be orders of magnitude smaller than expected from generation scenarios based on asymmetric depopulation of the Dirac cone. Our findings are of direct relevance for broadband optoelectronic devices based on topological-insulator surface currents.