5 research outputs found
Detecting the Kondo screening cloud around a quantum dot
A fundamental prediction of scaling theories of the Kondo effect is the
screening of an impurity spin by a cloud of electrons spread out over a
mesoscopic distance. This cloud has never been observed experimentally.
Recently, aspects of the Kondo effect have been observed in experiments on
quantum dots embedded in quantum wires. Since the length of the wire may be of
order the size of the screening cloud, such systems provide an ideal
opportunity to observe it. We point out that persistent current measurements in
a closed ring provide a conceptually simple way of detecting this fundamental
length scale.Comment: 4 pages, RevTex, 1 postscript figur
Kondo screening cloud effects in mesoscopic devices
We study how finite size effects may appear when a quantum dot in the Kondo
Coulomb blockade regime is embedded into a mesoscopic device with finite wires.
These finite size effects appear when the size of the mesoscopic device
containing the quantum dot is of the order of the size of Kondo cloud and
affect all thermodynamic and transport properties of the Kondo quantum dot. We
also generalize our results to the experimentally relevant case where the wires
contain several transverse modes/channels. Our results are based on
perturbation theory, Fermi liquid theory and slave boson mean field theory.Comment: 19 pages, 9 figure