A microscopic quantum model of nanoscale ballistic rectifiers

A microscopic model containing a 2×2 quantum-dot array connected to four leads is presented to describe the recent experiments on symmetry-broken mesoscopic semiconductor structure, the triangular antidot, which exhibited rectifying effect in the transverse current-voltage characteristics. It is opposite to the prediction of the linear Landauer-Buttiker formalism and is believed to come from the nonlinear effect. Basing on the non-equilibrium Green´s function technique, we find that the rectifying effect is a consequence of any asymmetry of the quantum-dot array along the transverse direction. This microscopic provides a possible benchmark to study more complicated rectifying properties.