In collaboration with Prof. Tokura (University of Tsukuba).
Variable-range hopping (VRH) transport is traditionally explained using the percolation picture of random resistor networks, where conduction is governed by the connectivity of a small subset of dominant bonds. In this project, we pursue a more statistical-mechanical viewpoint: instead of focusing only on bond connectivity, we analyze the collective organization of site voltages (the potential landscape) that emerges from the rate equations.
Our aim is an ambitious one\to bridge VRH theory with concepts familiar from critical phenomena and disordered spin systems (e.g., Ising and spin-glass theory). By introducing a pseudo-partition-function framework motivated by dissipation (Joule heating) and by studying correlations and fluctuations of the voltage field, we seek a principled route to macroscopic transport laws such as the Mott relation, beyond the standard percolation narrative.