Liquid-Hexatic-Solid phases in active and passive Brownian particles driven by stochastic birth-death events

The behaviour of active matter has been intensively investigated in the last decades partly because of its many applications to living systems. In this work we add stochastic birth-death dynamics to a system of particles with volume exclusion. This is a simple, but general biological ingredient and has not been studied in detail before. The number of particles in the system at long times depends on the birth and death rates, and on a parameter characterising the activity of self-propelled particles. We find liquid, solid and hexatic phases in the absence of activity. Which one of these phases is realised depends on the birth and death rates. In active systems we also find motility induced phase separation (MIPS) when the self-propulsion velocity is large and the birth rate small enough. In the MIPS phase the solid and liquid states coexist.



https://us02web.zoom.us/j/83829318876?pwd=Z2pqbUtIMEV3NUQvU0hpakp0NGtsUT09