Variable-Range Cotunneling and Conductivity of a Granular Metal
Abstract
The Efros-Shklovskii 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 << T_c, while it is inelastic (i.e., accompanied by creation of electron-hole pairs on a string of intermediate non-resonant grains) at T > T_c. The corresponding E-S temperature T_ES 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 much below T_c, while at T>T_c it is suppressed due to inelastic processes which destroy the interference.
- Publication:
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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:
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- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Disordered Systems and Neural Networks
- E-Print:
- Submitted to JETP Letters