Control over topological insulator photocurrents with light polarization
Author(s)
McIver, James
Hsieh, David
Steinberg, Hadar
Jarillo-Herrero, Pablo
Gedik, Nuh
Date Issued
December 2011
Journal
Nature Nanotechnology
Publisher
Nature Publishing Group
Citation
McIver, J. W. et al. “Control over topological insulator photocurrents with light polarization.” Nature Nanotechnology 7.2 (2011): 96-100.
Version
Author's final manuscript
Abstract
Three-dimensional topological insulators (1-3) represent a new quantum phase of
matter with spin-polarized surface states (4,5) that are protected from backscattering. The
static electronic properties of these surface states have been comprehensively imaged by
both photoemission (4-8) and tunneling (9,10) spectroscopies. Theorists have proposed that
topological surface states can also exhibit novel electronic responses to light, such as
topological quantum phase transitions (11-13) and spin-polarized electrical currents (14,15).
However, the effects of optically driving a topological insulator out of equilibrium have
remained largely unexplored experimentally, and no photocurrents have been measured.
Here we show that illuminating the topological insulator Bi(subscript 2)Se(subscript 3) with circularly polarized
light generates a photocurrent that originates from topological helical Dirac fermions, and
that reversing the helicity of the light reverses the direction of the photocurrent. We also
observe a photocurrent that is controlled by the linear polarization of light, and argue that
it may also have a topological surface state origin. This approach may allow the probing of
dynamic properties of topological insulators(11-15) and lead to novel opto-spintronic devices(16).
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike 3.0
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1038/nnano.2011.214
