Nonergodic subdiffusion from transient interactions with heterogeneous partners

摘要

Spatiotemporal disorder has been recently associated to the occurrence of anomalous nonergodic diffusionof molecular components in biological systems, but the underlying microscopic mechanism is still unclear. Weintroduce a model inwhich a particle performs continuous Brownian motionwith changes of diffusion coefficientsinduced by transient molecular interactions with diffusive binding partners. In spite of the exponential distributionof waiting times, the model shows subdiffusion and nonergodicity similar to the heavy-tailed continuous timerandom walk. The dependence of these properties on the density of binding partners is analyzed and discussed.Our work provides an experimentally testable microscopic model to investigate the nature of nonergodicity indisordered media.