V. M. Apel, Pedro A. Orellana, Monica Pacheco, E. V. Anda
In this work we investigate the transport properties of strongly correlated quantum dot in Kondo regime attached to two leads and side coupled to non interacting N sites quantum-ring (QR) pierced by magnetic flux. In order to calculate the transport properties we use the slave boson technique in the limit of infinite Coulomb repulsion (U \rightarrow 1) in a quantum dot (QD). We show that the differential conductance develops a sequence of Fano anti-resonances as a consequence of destructive interferences of N discrete quantum ring levels with continuous conducting channels. The interaction determines the Fano antiresonance line-shape, in the U = 1 limit the Fano antiresonances are asymmetric while in the case without interaction (U = 0) they are symmetric. We show that for weak or intermediate QD-QR coupling, the Fano factor depends strongly with the magnetic flux. To strong QD-QR coupling, the Fano factor does not depend on the magnetic flux and varies discontinuously between 1 and 1=2 values. In this strong coupling regime, we show from the information provided by the current and shot noise curves, that the transmission T(!) must be exactly a sequence of Lorentzian peaks.
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http://arxiv.org/abs/1205.1744
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