  Topological insulators and superconductors have attracted considerable
attention, and many different theoretical tools have been used to gain insight
into their properties. Here we investigate how perturbations can spread through
exemplary one-dimensional topological insulators and superconductors using
out-of-time ordered correlators. Out-of-time ordered correlators are often used
to consider how information becomes scrambled during quantum dynamics. The
wavefront of the out-of-time ordered correlator can be ballistic regardless of
the underlying system dynamics, and here we confirm that for topological free
fermion systems the wavefront spreads linearly at a characteristic butterfly
velocity. We pay special attention to the topologically protected edge states,
finding that "information" can become trapped in the edge states and
essentially decoupled from the bulk, surviving for relatively long times. We
consider different models with multiple possible edge states coexisting on a
single edge.
