Gate-modulated thermopower of disordered nanowires: II. Variable-range hopping regime
Abstract
We study the thermopower of a disordered nanowire in the field effect transistor
configuration. After a first paper devoted to the elastic coherent regime (Bosisio R., Fleury G.
and Pichard J.-L. 2014 New J. Phys. 16 035004), we consider here the inelastic activated regime
taking place at higher temperatures. In the case where charge transport is thermally assisted by
phonons (Mott Variable Range Hopping regime), we use the Miller-Abrahams random resistor
network model as recently adapted by Jiang et al. for thermoelectric transport. This approach
previously used to study the bulk of the nanowire impurity band is extended for studying its
edges. In this limit, we show that the typical thermopower is largely enhanced, attaining values
larger that 10 kB/e ∼ 1 mV K−1 and exhibiting a non-trivial behaviour as a function of the
temperature. A percolation theory by Zvyagin extended to disordered nanowires allows us to
account for the main observed edge behaviours of the thermopower.
Domains
Condensed Matter [cond-mat]
Origin : Files produced by the author(s)
Loading...