Fermiology of Strongly Spin-Orbit Coupled Superconductor Sn1-xInxTe and   its Implication to Topological Superconductivity
  We have performed angle-resolved photoemission spectroscopy of the strongly spin-orbit coupled low-carrier density superconductor Sn1-xInxTe (x = 0.045) to elucidate the electronic states relevant to the possible occurrence of topological superconductivity recently reported for this compound from point-contact spectroscopy. The obtained energy-band structure reveals a small holelike Fermi surface centered at the L point of the bulk Brillouin zone, together with a signature of a topological surface state which indicates that this superconductor is essentially a doped topological crystalline insulator characterized by band inversion and mirror symmetry. A comparison of the electronic states with a band-non-inverted superconductor possessing a similar Fermi surface structure, Pb1-xTlxTe, suggests that the anomalous behavior in the superconducting state of Sn1-xInxTe is likely to be related to the peculiar orbital characteristics of the bulk valence band and/or the presence of a topological surface state. 
T. Sato, Y. Tanaka, K. Nakayama, S. Souma, T. Takahashi, S. Sasaki, Z.   Ren, A. A. Taskin, Kouji Segawa, and Yoichi Ando
cond-mat.mes-hall cond-mat.str-el cond-mat.supr-con