Current relaxation in the Random Resistor cum Tunnelling Network Model through first-passage route: Regimes and time-scales

Numerically we study the bulk current relaxation in percolative Random Resistor cum Tunnelling Network (RRTN) model through a first-passage route. The RRTN considers an extra semi-classical barrier-crossing process over a voltage threshold within a framework of classical RRN bond percolation model. We identify the different temporal regimes of relaxation and corresponding phenomenological time-scales, which fix up the extents of different regimes. These time-scales were previously identified in Refs. Bhattacharya (2019) and Sen and Mozumdar (2007). We investigate on the distributions of these time-scales and observe that there exists a perfect correlation among them in the thermodynamic limit. We conclude that there exists a single time-scale which controls the RRTN dynamics. The variation of mean first-passage time .vs. system size seems to be due to sub-diffusive motion of charge carrier through the network. (C) 2021 Elsevier B.V. All rights reserved.