  In two-dimensional anomalous Floquet insulators, non-Hermitian boundary state
engineering can be used to completely separate chiral boundary states from bulk
bands in the quasienergy spectrum. The topological properties of such
spectrally separated boundary states are no longer restricted by the strict
bulk-boundary correspondence of Hermitian systems. We show that this additional
topological freedom enables one to faithfully transfer the topological
properties of a boundary attached to a Floquet insulator to a non-Hermitian
Floquet chain obtained by physically cutting off the boundary from the bulk. We
implement this scenario for a simple model of an anomalous Floquet insulator
with Hermitian and non-Hermitian boundaries, and discuss the relevance of our
construction for the experimental realization of non-Hermitian topological
phases that connect dimensions one and two.
