Heterogeneous response and non-Markovianity in the microrheology of semisolid viscoelastic materials

Recent works indicate that heterogeneous response and non-Markovianity may yield recognizable hallmarks in the microrheology of semisolid viscoelastic materials. Here we perform numerical simulations using a non-Markovian overdamped Langevin approach to explore how the microrheology experienced by probe particles immersed in an effective semisolid material can be influenced by its micro-heterogeneities. Our results show that, besides affecting the mean squared displacement, the time-dependent diffusion coefficient, and the shear moduli, the micro-heterogeneities lead to displacement distributions that deviate from the usual Gaussian behavior. In addition, our study provides an analytical way to characterize the micro-heterogeneities of semisolid viscoelastic materials through their microrheology.