Heterogeneity promotes criticality on flocking systems

We have considered a variation of the Vicsek model with vectorial noise where each one of the agents have their own noise amplitude normally distributed around a mean value, $\mu$, with standard deviation $\sigma$. First-order phase transition are observed for standard deviation $0\leq\sigma<\sigma_{tri}\approx0.11$, whereas for larger values, up to $\sigma=0.3$, a continuous phase transition occurs. For the particular case of $\sigma=0.20$ the continuous nature of the observed transition is characterized by means of finite-size scaling techniques, that also allow us to estimate the exponents driving the transition. A study of bands stability reveals that no band can form in this regime. Inspired by biological facts the perception heterogeneity, introduced in the model trough $\sigma$, allow us to tune the collective behaviour of the system.