Fermiology of possible topological superconductor Tl0.5Bi2Te3 derived   from hole-doped topological insulator
  We have performed angle-resolved photoemission spectroscopy on Tl0.5Bi2Te3, a possible topological superconductor derived from Bi2Te3. We found that the bulk Fermi surface consists of multiple three-dimensional hole pockets surrounding the Z point, produced by the direct hole doping into the valence band. The Dirac-cone surface state is well isolated from the bulk bands, and the surface chemical potential is variable in the entire band-gap range. Tl0.5Bi2Te3 thus provides an excellent platform to realize two-dimensional topological superconductivity through a proximity effect from the superconducting bulk. Also, the observed Fermi-surface topology provides a concrete basis for constructing theoretical models for bulk topological superconductivity in hole-doped topological insulators. 
C. X. Trang, Z. Wang, D. Takane, K. Nakayama, S. Souma, T. Sato, T.   Takahashi, A. A. Taskin, and Yoichi Ando
cond-mat.supr-con cond-mat.mes-hall