  The non-Hermitian skin effect describes the concentration of an extensive
number of eigenstates near the boundaries of certain dissipative systems. This
phenomenon has raised a huge interest in different areas of physics, including
photonics, deeply expanding our understanding of non-Hermitian systems and
opening up new avenues in both fundamental and applied aspects of topological
phenomena. The skin effect has been associated to a nontrivial point-gap
spectral topology and has been experimentally demonstrated in a variety of
synthetic matter systems, including photonic lattices. In most of physical
models exhibiting the non-Hermitian skin effect full or partial wave coherence
is generally assumed. Here we push the concept of skin effect into the fully
incoherent regime and show that rather generally (but not universally) the
non-Hermitian skin effect persists under dephasing dynamics. The results are
illustrated by considering incoherent light dynamics in non-Hermitian photonic
quantum walks.
