Andreev reflection from a topological superconductor with chiral symmetry
Andreev reflection from a topological superconductor with chiral symmetry
It was pointed out by Tewari and Sau that chiral symmetry ($H\ensuremath{\mapsto}\ensuremath{-}H$ if $\mathrm{e}\ensuremath{\leftrightarrow}\mathrm{h}$) of the Hamiltonian of electron-hole (e-h) excitations in an $N$-mode superconducting wire is associated with a topological quantum number $Q\ensuremath{\in}\mathbb{Z}$ (symmetry class BDI). Here we show that $Q=\mathrm{Tr}\phantom{\rule{0.16em}{0ex}}{r}_{\mathrm{he}}$ equals the trace of the matrix of Andreev …