Variable-Range Cotunneling and Conductivity of a Granular Metal
Abstract
The Efros-Shklovskii (E-S) law for the conductivity of granular metals is interpreted as a result of a variable-range cotunneling process. The cotunneling between distant resonant grains is predominantly elastic at low T ≤ Tc, while it is inelastic (i.e., accompanied by creation of electron-hole pairs on a string of intermediate non-resonant grains) at T ≥ Tc. The corresponding E-S temperature TES, in the latter case, is slightly (logarithmically) T dependent. The magnetoresistance in the two cases is different: it may be relatively strong and negative at T≪Tc , while, at T > Tc, it is suppressed due to inelastic processes, which destroy the interference.
- Publication:
-
Soviet Journal of Experimental and Theoretical Physics Letters
- Pub Date:
- March 2005
- DOI:
- 10.1134/1.1931015
- arXiv:
- arXiv:cond-mat/0502481
- Bibcode:
- 2005JETPL..81..277F
- Keywords:
-
- 73.23.Hk;
- 73.43.Qt;
- 73.63.‑b;
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Disordered Systems and Neural Networks
- E-Print:
- Submitted to JETP Letters