  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.
