Observation of Topological Order in a Superconducting Doped Topological Insulator

Author

Lewis Andrew Wray
Su-Yang Xu
Yuqi Xia
Yew San Hor, Missouri University of Science and TechnologyFollow
Dong Qian
Alexei V. Fedorov
Hsin Lin
Arun Bansil
Robert Joseph Cava
M. Zahid Hasan

Abstract

Experimental observation of topological order in three-dimensional bulk solids has recently led to a flurry of research activity^1-21. Unlike the two-dimensional electron gas or quantum Hall systems, three-dimensional topological insulators can harbour superconductivity and magnetism, making it possible to study the interplay between topologically ordered phases and broken-symmetry states. One outcome of this interplay is the possible realization of Majorana fermions-quasiparticles that are their own antiparticles-on topological surfaces, which is of great interest in fundamental physics^9-13,22-24. Here we present measurements of the bulk and surface electron dynamics in Bi₂ Se₃ doped with copper with a transition temperature T_c up to 3.8 K, observing its topological character for the first time. Our data show that superconductivity occurs in a bulk relativistic quasiparticle regime where an unusual doping mechanism causes the spin-polarized topological surface states to remain well preserved at the Fermi level of the superconductor where Cooper pairing takes place. These results suggest that the electron dynamics in superconducting Bi₂ Se₃ are suitable for trapping non-Abelian Majorana fermions. Details of our observations constitute important clues for developing a general theory of topological superconductivity in doped topological insulators.

Recommended Citation

L. A. Wray and S. Xu and Y. Xia and Y. S. Hor and D. Qian and A. V. Fedorov and H. Lin and A. Bansil and R. J. Cava and M. Z. Hasan, "Observation of Topological Order in a Superconducting Doped Topological Insulator," Nature Physics, vol. 6, no. 11, pp. 855 - 859, Nature Publishing Group, Nov 2010.

The definitive version is available at https://doi.org/10.1038/nphys1762

Department(s)

Physics

International Standard Serial Number (ISSN)

1745-2473

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2010 Nature Publishing Group, All rights reserved.

Publication Date

01 Nov 2010