Large Gap Topological Insulator Bi2Te3 with a Single Dirac Cone on the Surface

Y. L. Chen; J. G. Analytis; J. H. Chu; Z. K. Liu; S. K. Mo; X. L. Qi; H. J. Zhang; D. H. Lu; X. Dai; Z. Fang; S. C. Zhang; I. R. Fisher; Z. Hussain; Z. X. Shen

paper

Large Gap Topological Insulator Bi2Te3 with a Single Dirac Cone on the Surface

arXiv:0904.1829

Abstract

We investigate the surface state of Bi $_{2}$ Te $_{3}$ using angle resolved photoemission spectroscopy (ARPES) and transport measurements. By scanning over the entire Brillouin zone (BZ), we demonstrate that the surface state consists of a single non-degenerate Dirac cone centered at the $Γ$ point. Furthermore, with appropriate hole (Sn) doping to counteract intrinsic n-type doping from vacancy and anti-site defects, the Fermi level can be tuned to intersect only the surface states, indicating a full energy gap for the bulk states, consistent with a carrier sign change near this doping in transport properties. Our experimental results establish for the first time that Bi $_{2}$ Te $_{3}$ is a three dimensional topological insulator with a single Dirac cone on the surface, as predicted by a recent theory.

Submitted for publication on March 03, 2009