2023/11/16 by Hara, Yusuke, Mizuno, Hideyuki, Ikeda, Atsushi
#Disordered Systems and Neural Networks (cond-mat.dis-nn) #FOS: Physical sciences #Soft Condensed Matter (cond-mat.soft)
paper · doi:10.48550/arxiv.2311.09509
In the jamming transition of monodisperse packings, spatial heterogeneity is irrelevant as the transition is described by mean-field theories. Here, we show that this situation drastically changes if the particle-size dispersity is large enough. We use computer simulations to study the structural and vibrational properties of bidisperse sphere packings with a large size ratio. Near the critical point, the small particles tend to form clusters, leading to the emergence of large-scale structural heterogeneity. Concomitantly, the low-frequency vibrations are significantly enhanced compared to those in monodisperse packings, and their density of states follows a linear law with the frequency. We numerically and theoretically demonstrate that these behaviors of the structural heterogeneity and the low-frequency vibrations are intimately connected. The present work suggests that the nature of heterogeneous packings is markedly different from that of homogeneous packings.