Abstract

The electronic structure of Bi2Te3 covered by noble metals is investigated by first-principles calculations. The Dirac surface state of the topological insulator Bi2Te3 hybridizes with the sp states of the noble metal, which gives rise to strong reorganization of the surface electronic structure. Striking features of the modified Dirac surface state are (i) the introduction of new Dirac points within the fundamental band gap of Bi2Te3, (ii) a very weak dispersion, and (iii) a multisheeted Fermi surface which results in an orientation-dependent number of conducting channels in the fundamental band gap of Bi2Te3. Our findings have impact for spin-dependent surface transport.