Quantum interference effects on the electronic transmission through quantum dot molecules

R. H. ROMERO; D. A. LOVEY; D. S. ACOSTA CODEN ; S. S. GOMEZ

Quantum Dot Molecules (Lecture Notes in Nanoscale Science and Technology)

Springer

Año: 2014; p. 259 - 280

Quantum interference allows to enhance or to cancel, total or partially, the response of the system beyond the simple classical additive behaviour. Such an effect can pose a problem to be avoided but also could provide new capabilities to the device with respect to its classical counterpart. Two remarkable eects arose from this quantum behaviour, namely, the Fano and the Aharonov-Bohm effects. In this Chapter, we will show their theoretical explanations and experimental demonstrations in nanoscale structures. On one hand, the ability of tuning the device configuration and parameters, allows one to control its response to externally applied fields or voltages. The modication of the charge transport through the nanostructure, provides useful information on the material properties as well as to design new applications with unprecedented functionalities. By theoretical calculations we show that the model studied here provides a simple picture for understanding several measured effects, such as the change in the interference pattern in the AB period as the interdot coupling is turned on, the tuning of the resonances and antiresonances at a given arbitrary energy as well as the enhancement of the transmission through one the arms of the AB ring by applying gate voltages, and the cancellation of antiresonces by application of a magnetic field.