"Hopping transport through a nanoconstriction controlled by a single hop"
Prof. Veniamin Kozub
The Ioffe Institute, St. Petersburg
Hopping transport through a point contact between two bulk semiconductors is
considered for the case when the contact size is much smaller than a typical
hopping length in the bulk. In this case the conductance is controlled by a
single hop between the two sites located on the opposite banks of the contact.
For variable range hopping (VRH) the choice of the pair depends on
temperature,
and the temperature dependence of the conductance exhibits exponentially
large mesoscopic fluctuations. For large enough voltage the conductance is
strongly nonlinear and also exhibits giant fluctuations as a result of
"switching" between different "critical pairs". It also exhibits regions of
negative differential resistance due to resonant tunneling effective at some
"resonant" values of the bias. At higher biases the nonlinear I(V) curve
tends to a smooth one (I proportional to V2).
Host: Prof. Amnon Aharony, x8558
|