Observation of a Warped Helical Spin Texture in Bi[subscript 2]Se[subscript 3] from Circular Dichroism Angle-Resolved Photoemission Spectroscopy
Author(s)
Wang, Y. H.; Hsieh, David; Pilon, Daniel Victor; Fu, Liang; Gardner, Dillon Richard; Gedik, Nuh; Lee, Young S.; ... Show more Show less
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Alternative title
Observation of a Warped Helical Spin Texture in Bi2Se3 from Circular Dichroism Angle-Resolved Photoemission Spectroscopy
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Show full item recordAbstract
A differential coupling of topological surface states to left- versus right-circularly polarized light is the basis of many optospintronics applications of topological insulators. Here we report direct evidence of circular dichroism from the surface states of Bi[subscript 2]Se[subscript 3] using laser-based time-of-flight angle-resolved photoemission spectroscopy. By employing a novel sample rotational analysis, we resolve unusual modulations in the circular dichroism photoemission pattern as a function of both energy and momentum, which perfectly mimic the predicted but hitherto unobserved three-dimensional warped spin texture of the surface states. By developing a microscopic theory of photoemission from topological surface states, we show that this correlation is a natural consequence of spin-orbit coupling. These results suggest that our technique may be a powerful probe of the spin texture of spin-orbit coupled materials in general.
Date issued
2011-11Department
Massachusetts Institute of Technology. Department of PhysicsJournal
Physical Review Letters
Publisher
American Physical Society (APS)
Citation
Wang, Y. et al. “Observation of a Warped Helical Spin Texture in Bi_{2}Se_{3} from Circular Dichroism Angle-Resolved Photoemission Spectroscopy.” Physical Review Letters 107.20 (2011): n. pag. Web. 8 Mar. 2012. © 2011 American Physical Society
Version: Final published version
ISSN
0031-9007
1079-7114