  We analyze junctions between noninteracting fermionic topological phases. A
closed-form condition for the existence of localized modes at the interface is
derived using the transfer matrix approach. These analytical conditions as well
as numerical exact diagonalization are used to study interfaces between Weyl
semimetals. We observe a Fermi arc reconstruction at the interface, leading to
curves of zero energy modes in the interface Brillouin zone. These are stable
even in certain cases where the two Weyl semimetals differ only in their Fermi
arc connectivities.

Mesoscale and Nanoscale Physics;Other Condensed Matter