1211.4663 (Tetsuro Habe et al.)

Gapped energy spectra around the Dirac node at the surface of a 3D
topological insulator in the presence of the time-reversal symmetry    [PDF]

Tetsuro Habe, Yasuhiro Asano

We discuss the excitation spectra around the Dirac node on a surface of a three-dimensional topological insulator. By using the diagrammatic expansion, we show that the coupling of an electron with the gauge field in the presence of impurity scatterings opens a gap around the Dirac node. The results are consistent with a recent experimental finding by T. Sato,et. al.[ Nature Phys. \textbf{7}, 840 (2011)]. We also discuss the consistency between the present results and the bulk-boundary correspondence of the topological insulator in the presence of time reversal symmetry. The conclusion can be applied any two dimensional massless fermions.

View original: http://arxiv.org/abs/1211.4663