ZhETF, Vol. 148,
p. 584 (September 2015)
(English translation - JETP,
Vol. 121, No. 3,
available online at www.springer.com
SURFACE STATES IN A 3D TOPOLOGICAL INSULATOR: THE ROLE OF HEXAGONAL WARPING AND CURVATURE
Received: May 3, 2015
We explore a combined effect of hexagonal warping and a finite effective mass on both the tunneling density of electronic surface states and the structure of Landau levels of 3D topological insulators. We find the increasing warping to transform the square-root van Hove singularity into a logarithmic one. For moderate warping, an additional logarithmic singularity and a jump in the tunneling density of surface states appear. By combining the perturbation theory and the WKB approximation, we calculate the Landau levels in the presence of hexagonal warping. We predict that due to the degeneracy removal, the evolution of Landau levels in the magnetic field is drastically modified.