Strong and Weak 3D Topological Insulators Probed by Surface Science Methods

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...

Strong Topological Regularity and Weak Regularity of Banach Algebras

In this article we study two different generalizations of von Neumann regularity, namely strong topological regularity and weak regularity, in the Banach algebra context. We show that both are hereditary properties and under certain assumptions, weak regularity implies strong topological regularity. Then we consider strong topological regularity of certain concrete algebras. Moreover we obtain ...

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...

Topological insulators: The surface surfaces.

Surface States of Topological Insulators

We introduce a topological boundary condition to study the surface states of topological insulators within a long-wavelength four-band model. We find that the Dirac point energy, the band curvature, and the spin texture of surface states are crystal-face dependent. For an arbitrary termination of a bulk crystal, the energy of the symmetry protected Dirac point is determined by the bulk physics ...