Observation of Unconventional Quantum Spin Textures in Topological Insulators

Abstract

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.

Department(s)

Physics

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)

0036-8075

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2009 American Association for the Advancement of Science (AAAS), All rights reserved.

Publication Date

01 Feb 2009

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