In the past few years, a new state of quantum matter known as the time-reversal-invariant topological insulator has been predicted theoretically and realized experimentally. All of the topological insulators discovered so far in experiment are inversion symmetric - except for strained HgTe, which has weak inversion asymmetry, a small bulk gap but no bulk charge polarization. Strong inversion asymmetry in topological insulators would not only lead to many interesting phenomena, such as crystalline-surface-dependent topological electronic states, pyroelectricity and intrinsic topological p-n junctions, but would also serve as an ideal platform for the realization of topological magneto-electric effects, which result from the modification of Maxwell equations in topological insulators. Here we report the discovery of a strong inversion asymmetric topological insulator phase in BiTeCl by angle-resolved photoemission spectroscopy, which reveals Dirac surface states and crystalline-surface-dependent electronic structures. Moreover, we observe a tenfold increase of the bulk energy gap in BiTeCl over the weak inversion asymmetric topological insulator HgTe, making it a promising platform for topological phenomena and possible applications at high temperature. © 2013 Macmillan Publishers Limited.
CITATION STYLE
Chen, Y. L., Kanou, M., Liu, Z. K., Zhang, H. J., Sobota, J. A., Leuenberger, D., … Sasagawa, T. (2013). Discovery of a single topological Dirac fermion in the strong inversion asymmetric compound BiTeCl. Nature Physics, 9(11), 704–708. https://doi.org/10.1038/nphys2768
Mendeley helps you to discover research relevant for your work.