Information and motility exchange in collectives of active particles

Understand

We examine the interplay of motility and information exchange in a model of run-and-tumble active particles where the particle's motility is encoded as a bit of information that can be exchanged upon contact according to the rules of AND and OR logic gates in a circuit.

• Motile AND particles become non-motile upon contact with a non-motile particle.
• Conversely, motile OR particles remain motile upon collision with their non-motile counterparts.
• AND particles that have become non-motile additionally "reawaken", i.e., recover their motility, at a fixed rate $\mu$, as in the SIS (Susceptible, Infected, Susceptible) model of epidemic spreading, where an infected agent can become healthy again, but keeps no memory of the recent infection, hence it is susceptible to a renewed infection.