English

Miller-Abrahams random resistor network, Mott random walk and 2-scale homogenization

Mathematical Physics 2022-03-14 v3 Analysis of PDEs math.MP Probability

Abstract

The Miller-Abrahams (MA) random resistor network is given by a complete graph on a marked simple point process with edge conductivities depending on the marks and decaying exponentially in the edge length. As Mott random walk, it is an effective model to study Mott variable range hopping in amorphous solids as doped semiconductors. By using 2-scale homogenization we prove that a.s. the infinite volume conductivity of the MA resistor network is given by an effective homogenized matrix DD. Moreover DD admits a variational characterization and equals the limiting diffusion matrix of Mott random walk. This result clarifies the relation between the two models and it also allows to extend to the MA resistor network the existing bounds on DD in agreement with the physical Mott law [12,14]. The latter concerns the low temperature stretched exponential decay of conductivity in amorphous solids. The techniques developed here can be applied to other models, as e.g. the random conductance model [11], without ellipticity assumptions.

Keywords

Cite

@article{arxiv.2002.03441,
  title  = {Miller-Abrahams random resistor network, Mott random walk and 2-scale homogenization},
  author = {Alessandra Faggionato},
  journal= {arXiv preprint arXiv:2002.03441},
  year   = {2022}
}

Comments

41 pages, 1 figure. Corrected Theorem 2 and its proof. This preprint is and will remain unpublished. The results contained here have been generalized to a very large class of random resistor networks on point processes in arXiv:2108.11258. Hence the present results are just a special subcase of the ones in arXiv:2108.11258

R2 v1 2026-06-23T13:35:54.089Z