2024/03/18(Mon) 10:30 -12:30 五樓第一會議室 5F, 1st Meeting Room
Title
Effect of interaction softness on the collective properties of active Brownian particles (Online)
Speaker
Dr. Amitabha Nandi (Indian Institute of Technology Bombay, Mumbai, India)Abstract
Motility-induced phase separation (MIPS), exhibited by a system of active Brownian particles with repulsive interaction has been extensively studied during the last decade. In this talk, we will discuss the effect of a crucial parameter, namely the softness of the inter-particle repulsion, on MIPS. Using model of active Brownian discs interacting via a generalized Weeks-Chandler-Andersen (WCA) potential, we found that increasing the particle softness leads to a delayed transition to the MIPS state. Furthermore using a different form of inter-particle interaction -- a harmonic potential that allows a larger particle overlap, we found that interaction softness destabilizes the MIPS phase, forming a spanning porous cluster. This soft limit can also be reached by increasing particle motility over a critical value at which the system exhibits all of the characteristics of a standard percolation transition. We extended our study to study a binary mixture of hard and soft particles -- we found that apart from the transitions seen for the homogeneous system, there is a complex structure formation within the MIPS state, which depends on the relative softness of the binary system. With these additional phases, the phase-diagram of repulsive active particles appears to be more complex than previously perceived.
Language
演講語言 (Language): in English