  In an experimental study of Andreev reflection (AR) in normal
metal/superconductor (N-S) devices featuring a superconducting topological
insulator CuxBi2Se3 [arXiv:1301.1030], Peng et. al. reported the reproducible
experimental observation of archetypical double-peak AR spectra for finite
barrier strength in N-S junctions, which clearly indicates the absence of
zero-energy peak in density of states and thus rules out theoretically
predicted zero-energy Majorana fermions in CuxBi2Se3. This report casts doubt
on previous claims of CuxBi2Se3 as a topological superconductor. Here we
clarify an inaccurate understanding which claims that no spectroscopic
information can be extracted from N-S point-contacts showing conductance dips
at finite bias. Such a clarification of the origin of conductance dips in AR
spectra is important for future research in this field.
