Observation of Unconventional Quantum Spin Textures in Topological Insulators
A topologically ordered material is characterized by a rare quantum organization of electrons that evades the conventional spontaneously broken symmetry-based classification of condensed matter. Exotic spin-transport phenomena, such as the dissipationless quantum spin Hall effect, have been speculated to originate from a topological order whose identification requires a spin-sensitive measurement, which does not exist to this date in any system. Using Mott polarimetry, we probed the spin degrees of freedom and demonstrated that topological quantum numbers are completely determined from spin texture-imaging measurements. Applying this method to Sb and Bi1-xSbx, we identified the origin of its topological order and unusual chiral properties. These results taken together constitute the first observation of surface electrons collectively carrying a topological quantum Berry's phase and definite spin chirality, which are the key electronic properties component for realizing topological quantum computing bits with intrinsic spin Hall-like topological phenomena.
D. Hsieh and Y. Xia and L. A. Wray and D. Qian and A. Pal and J. H. Dil and J. Osterwalder and F. Meier and G. Bihlmayer and C. L. Kane and Y. S. Hor and R. J. Cava and M. Z. Hasan, "Observation of Unconventional Quantum Spin Textures in Topological Insulators," Science, vol. 323, no. 5916, pp. 919-922, American Association for the Advancement of Science (AAAS), Feb 2009.
The definitive version is available at http://dx.doi.org/10.1126/science.1167733
Keywords and Phrases
Gold; Quantum Dot; Electron; Imaging Method; Quantum Mechanics; Chirality; Electron; Imaging And Display; Insulator Element; Magnetic Field; Polarimetry; Spectroscopy
International Standard Serial Number (ISSN)
Article - Journal
© 2009 American Association for the Advancement of Science (AAAS), All rights reserved.