Self-organized criticality below the glass transition

We obtain evidence that the dynamics of glassy systems below the glass transition is characterized by self-organized criticality. Using molecular-dynamics simulations of a model glass-former we identify clusters of cooperatively jumping particles. We find string-like clusters whose size is power-law-distributed not only close to T-C but for all temperatures below T-C, indicating self-organized criticality which we interpret as a freezing in of critical behavior.