Two early-stage inverse power-law dyamics in nonlinear complex systems far-from equilibrium

Abstract

We consider the dynamics of the charge carriers in a tunneling-enhanced percolation network, named as a Random Resistor cum Tunneling-bond Network (RRTN), where we allow tunneling in the gap between two randomly thrown nearest neighbour metallic bonds only. Our earlier studies involve the dc and the ac nonlinear response, the percolative aspects, dielectric breakdown, low-temperature variable range hopping (VRH) conduction, etc. in the RRTN. Here we study the non-equilibrium dynamics of the carriers. With two far-from- equilibrium, initial inverse power-law relaxations extending over several decades, the dynamics has a lot of similarities with a wide variety of naturally occuring avalance-like, run-away phenomena in driven, disordered systems with statistically correlated randomness. In the power-law regime, the RRTN violates the Boltzmann's (or Debye) relaxation time approximation strongly. Beyond this regime, the response relaxes exponentially fast (acquires one time-scale) to a steady-state, and thus the relaxation approximation becomes exact.