The Impact of Active Components on the Jamming Transition in Granular Mixtures

The jamming transition in granular materials has been extensively studied in both active and passive systems. In purely active granular systems, the activity of particles plays a crucial role in unjamming the system. However, many real-world granular systems, such as soils containing living organisms, consist of both active and passive particles, and the effect of these active components on the jamming transition in such mixtures remains largely unexplored. In this study, we employ computational simulations of mixtures of passive and active soft Brownian particles to investigate how active particles influence the unjamming behavior of the system. By varying the proportion of active particles, we found that even a small fraction can significantly reduce jamming, with systems containing 50% active particles displaying unjamming behavior comparable to fully active systems. Additionally, we examined the influence of relative size between active and passive particles and preferred movement directions of the active particles on the unjamming effect. These findings provide quantitative insights into the role of living organisms in the mechanical stability of natural granular materials and offer guidelines for controlling jamming by introducing active components.