We explore the stability of far-from-equilibrium metastable states of a three-dimensional Coulomb glass at zero temperature by studying charge avalanches triggered by a slowly varying external electric field. Surprisingly, we identify a sharply defined dynamical (“depinning”) phase transition from stationary to nonstationary charge displacement at a critical value of the external electric field. Using particle-conserving dynamics, scale-free system-spanning avalanches are observed only at the critical field. We show that the qualitative features of this depinning transition are completely different for an equivalent short-range model, highlighting the key importance of long-range interactions for nonequilibrium dynamics of Coulomb glasses.
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Andresen, J. C., Pramudya, Y., Katzgraber, H. G., Thomas, C. K., Zimanyi, G. T., & Dobrosavljević, V. (2016). Charge avalanches and depinning in the Coulomb glass: The role of long-range interactions. Physical Review B, 93, . https://doi.org/10.1103/PhysRevB.93.094429