Transport in a mesoscopic ring with a quantum dot: from the Coulomb blockade regime to the Kondo effect

Valeria Ferrari, Guillermo Chiappe, Enrique Anda

Published 2000-10-24Version 1

The system described in this work consists of a quantum dot inserted in a mesoscopic ring threaded by a magnetic flux. Our aim is to present a complete description for this device and to predict the physics of a experiment with these features. We have proposed a model that takes into account the conditions that are usual in experiments with quantum dots and mesoscopic systems. In order to solve the model, we develop a methodology to find the Green's functions of the system by means of proper approximations. This system presents persistent currents as a function of a gate potential applied to the quantum dot. We have studied the influence of both the interaction between electrons and the hybridization between the ring and the dot. We have found several regimes that describe different physical phenomena involved in the system. These regimes range from the phenomenon of Coulomb Blockade (in the high correlation limit) to a quasi non interacting regime. Between these two limits we have found an intermediate regime where the Kondo effect shows up.