Prediction of Weak Topological Insulators in Layered Semiconductors

Layered Topological Crystalline Insulators.

Topological crystalline insulators (TCIs) are insulating materials whose topological property relies on generic crystalline symmetries. Based on first-principles calculations, we study a three-dimensional (3D) crystal constructed by stacking two-dimensional TCI layers. Depending on the interlayer interaction, the layered crystal can realize diverse 3D topological phases characterized by two mir...

Competing weak localization and weak antilocalization in ultrathin topological insulators.

We demonstrate evidence of a surface gap opening in topological insulator (TI) thin films of (Bi(0.57)Sb(0.43))(2)Te(3) below six quintuple layers through transport and scanning tunneling spectroscopy measurements. By effective tuning the Fermi level via gate-voltage control, we unveil a striking competition between weak localization and weak antilocalization at low magnetic fields in nonmagnet...

Disordered weak and strong topological insulators.

A global phase diagram of disordered weak and strong topological insulators is established numerically. As expected, the location of the phase boundaries is renormalized by disorder, a feature recognized in the study of the so-called topological Anderson insulator. Here, we report unexpected quantization, i.e., robustness against disorder of the conductance peaks on these phase boundaries. Anot...

Topological insulators

Screening of positrons in semiconductors and insulators.

Rights: © 1989 American Physical Society (APS). This is the accepted version of the following article: Puska, M. J. & Mäkinen, S. & Manninen, M. & Nieminen, Risto M. 1989. Screening of positrons in semiconductors and insulators. Physical Review B. Volume 39, Issue 11. 7666-7679. ISSN 1550-235X (electronic). DOI: 10.1103/physrevb.39.7666, which has been published in final form at http://journals...