  In this work we study a two-dimensional system composed by Active Brownian
Particles (ABPs) interacting via a repulsive potential with two-length-scales,
a soft shell and a hard-core. Depending on the ratio between the strength of
the soft shell barrier and the activity, we find two regimes: If this ratio is
much larger or smaller than 1, the observed behaviour is comparable with ABPs
interacting via a single length-scale potential. If this ratio is similar to 1,
the two length-scales are relevant for both structure and dynamical properties.
On the structural side, when the system exhibits a motility induced phase
separation, the dense phase is characterised by new and more complex structures
compared with the hexatic phase observed in single length-scale systems. On the
dynamical side, as far as we are aware, this is the first representation of an
anomalous dynamics in active particles.
