  We investigate numerically the Andreev spectrum of a multichannel mesoscopic
quantum wire (N) with high spin-orbit interaction coupled to superconducting
electrodes (S), contrasting topological and non topological behaviors.
  In the non topological case, modeled by a square lattice with Rashba
interactions, we find that as soon as the normal quantum wires can host several
conduction channels, the spin degeneracy of Andreev levels is lifted by a phase
difference between the S reservoirs which breaks time reversal symmetry in zero
Zeeman field. The Andreev states remain degenerate at phases multiple of $\pi$
for which time reversal symmetry is preserved, giving rise to level crossings
which are not lifted by disorder. In contrast with the dc Josephson current,
the finite frequency admittance (susceptibility) is very sensitive to these
level crossings and the lifting of their degeneracy by a small Zeeman field.
More interesting is the case of the hexagonal lattice with next nearest
neighbor spin-orbit interactions which exhibit 1D topological helical edge
states \cite{Kane2005}. The finite frequency admittance carries then a very
specific signature at low temperature of a protected Andreev level crossing at
$\pi$ and zero energy in the form of a sharp peak split by a Zeeman field.
