Electronic states of possible topological superconductor derived from hole-doped topological insulator

Topological superconductors (TSCs) have become a research frontier in the study of topologically ordered electronic states of matter. Although there has been a considerable amount of research to realize TSCs, the relationship between the electronic states and the topological superconductivity is under intensive debate. Recently, a new platform of TSCs was discovered in thallium (Tl)-doped Bi₂Te₃. This material shows the superconductivity of T_c = 2.28 K with the SC volume fraction as high as 95% [1]. To elucidate the topological superconductivity from the viewpoint of electronic states, we have performed angle-resolved photoemission spectroscopy (ARPES) of Tl_xBi₂Te₃ (TBT) (x = 0.5), and determined the electronic band structure of bulk and surface states [2].
We have established the bulk Fermi surface originated from the direct hole doping into the valence-band top. We also found from the band dispersion the topological surface states that can be controlled by surface-aging technique, making TBT an excellent platform to realize 2D TSC. In this presentation, we will show our ARPES results in detail and discuss electronic states relevant to the occurrence of superconductivity.
[1] Z. Wang et al., Chem. Mater. 28, 779 (2016).
[2] C. X. Trang et al., Phys. Rev. B 93, 241103(R) (2016).