  A collection of self-propelled particles (SPPs) shows coherent motion and
exhibits a true long range ordered (LRO) state in two dimensions. Various
studies show that the presence of spatial inhomogeneities can destroy the usual
long-range ordering in the system. However, the effects of inhomogeneity due to
the intrinsic properties of the particles are barely addressed. In this paper
we consider a collection of polar SPPs moving with inhomogeneous speed (IS) on
a two dimensional substrate, which can arise due to varying physical strength
of the individual particle. To our surprise, the IS not only preserves the
usual long-range ordering present in the homogeneous speed models but also
induces faster ordering in the system. Furthermore, The response of the flock
to an external perturbation is also faster, compared to Vicsek like model
systems, due to the frequent update of neighbors of each SPP in the presence of
the IS. Therefore, our study shows that the IS can help in faster information
transfer in the moving flock.

Soft Condensed Matter;Statistical Mechanics