Model non-linear nano-electronic device

We show a simple model for a non-linear nano-electronic device displaying a range of current-voltage characteristics including negative differential resistance, multistability and rectification. The tight-binding model for the device consists of a pair of coupled quantum dots attached to two semi-infinite linear mono-atomic chains. Non-linearity is introduced via electron-electron coulomb repulsion through an onsite Hubbard U. We study the mean-field electronic structure of the device as a function of applied potential difference for a range of values of the intra-device coupling and coupling to the leads. (C) 2008 Elsevier B.V. All rights reserved.