28 research outputs found
Electron correlation resonances in the transport through a single quantum level
Correlation effects in the transport properties of a single quantum level
coupled to electron reservoirs are discussed theoretically using a
non-equilibrium Green functions approach. Our method is based on the
introduction of a second-order self-energy associated with the Coulomb
interaction that consistently eliminates the pathologies found in previous
perturbative calculations. We present results for the current-voltage
characteristic illustrating the different correlation effects that may be found
in this system, including the Kondo anomaly and Coulomb blockade. We finally
discuss the experimental conditions for the simultaneous observation of these
effects in an ultrasmall quantum dot.Comment: 4 pages (two columns), 3 figures under reques
Transport in Coupled Quantum Dots: Kondo Effect Versus Anti-Ferromagnetic Correlation
The interplay between the Kondo effect and the inter-dot magnetic interaction
in a coupled-dot system is studied. An exact result for the transport
properties at zero temperature is obtained by diagonalizing a cluster, composed
by the double-dot and its vicinity, which is connected to leads. It is shown
that the system goes continuously from the Kondo regime to an
anti-ferromagnetic state as the inter-dot interaction is increased. The
conductance, the charge at the dots and the spin-spin correlation are obtained
as a function of the gate potential.Comment: 4 pages, 3 postscript figures. Submitted to PR