  The identification of topological superconductors usually involves searching
for in-gap modes that are protected by topology. However, in the current
experimental settings, the smoking-gun evidence of these in-gap modes is still
lacking. In this work, we propose to distinguish between two-dimensional
conventional s-wave and topological p-wave superconductors by above-gap
transport signatures. Our method utilizes the emergence of Tomasch oscillations
of quasiparticles in a junction consisting of a superconductor sandwiched
between two metallic leads. We demonstrate that the behavior of the
oscillations in conductance as a function of the interface barriers provides a
distinctive signature for s-wave and p-wave superconductors. Specifically, the
oscillations become weaker as the barrier strength increases in s-wave
superconductors, while they become more pronounced in p-wave superconductors,
which we prove to be a direct manifestation of the pairing symmetries. Our
method opens a new route for identifying topological superconductors through
above-gap transport.
