Abstract
We study the hopping conduction in a composite made of straight metallic nanowires randomly and isotropically suspended in an insulator. Uncontrolled donors and acceptors in the insulator lead to random charging of wires and, hence, to a finite bare density of states at the Fermi level. Then the Coulomb interactions between electrons of distant wires result in the soft Coulomb gap. At low temperatures the conductivity σ is due to variable range hopping of electrons between wires and obeys the Efros-Shklovskii (ES) law ln σ - (TES T)1 2. We show that TES 1 (n L3) 2, where n is the concentration of wires and L is the wire length. Due to enhanced screening of Coulomb potentials, at large enough n L3 the ES law is replaced by the Mott law.
Original language | English (US) |
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Article number | 054205 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 74 |
Issue number | 5 |
DOIs | |
State | Published - 2006 |