It is well established that dilute active dopants can melt an arrested amorphous solid by enhancing cage breaking and accelerating structural relaxation. Yet it remains unclear whether increasing persistence simply amplifies this effective melting or instead reorganizes the fluidization mechanism itself. Here we show that, in a minimal active-passive mixture, increasing persistence drives a crossover from homogeneous fluidization to a localized mechanical instability, demonstrating that sustained active forcing restructures relaxation in space rather than merely strengthening it. Persistent dopants accumulate stress and nucleate voids as their mechanically perturbed regions overlap. In this regime, rearrangements localize at void boundaries, and active and passive particles exhibit comparable mobility, producing dynamics reminiscent of crowd mosh pits. Persistence therefore reorganizes fluidization through stress accumulation and confinement, revealing a distinct nonequilibrium localization mechanism in disordered solids.
Max Planck Institute for the Physics of Complex Systems（马克斯·普朗克复杂系统物理研究所）；Ludwig-Maximilians-Universität München（慕尼黑路德维希-马克西米利安大学）；Cluster of Excellence Physics of Life, TU Dresden（德累斯顿工业大学生命物理卓越集群）
Collective Cell Fluidity Controls Active Prestress Transmission in Cell-Extracellular-Matrix Tissues
School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University（上海交通大学化学化工学院）；Physics Department, Syracuse University（雪城大学物理系）；Indian Creek Farm（印度溪农场）
Scaling the glassy dynamics of active particles: Tunable fragility and reentrance
Tata Institute of Fundamental Research（塔塔基础研究所）；University of Göttingen（哥廷根大学）；CNRS UMR 7083, ESPCI Paris, PSL Research University（法国国家科学研究中心UMR 7083，巴黎高等物理化工学院，PSL研究大学）
