Title: Hidden chiral symmetries in BDI multichannel Kitaev chains,
Abstract: Realistic implementations of the Kitaev chain require, in general, the
introduction of extra internal degrees of freedom. In the present work, we
discuss the presence of hidden BDI symmetries for free Hamiltonians describing
systems with an arbitrary number of internal degrees of freedom. We generalize
results of a spinfull Kitaev chain to construct a Hamiltonian with $n$ internal
degrees of freedom and obtain the corresponding hidden chiral symmetry. As an
explicit application of this generalized result, we exploit by analytical and
numerical calculations the case of a spinful 2-band Kitaev chain, which can
host up to 4 Majorana bound states. We also observe the appearence of minigap
states, when chiral symmetry is broken.