Quantum dots with even number of electrons: kondo effect in a finite magnetic field
We show that the Kondo effect can be induced by an external magnetic field in quantum dots with an even number of electrons. If the Zeeman energy B is close to the single-particle level spacing Delta in the dot, the scattering of the conduction electrons from the dot is dominated by an anisotropic exchange interaction. A Kondo resonance then occurs despite the fact that B exceeds by far the Kondo temperature T(K). As a result, at low temperatures T<<T(K) the differential conductance approaches a unitary limit G(K) approximately e(2)/piPlanck's over 2pi. A possible experimental realization of this effect is discussed.
Pustilnik
M
Danish Institute of Fundamental Metrology, Anker Engelunds Vej 1, Building 307, DK-2800 Lyngby, Denmark and Orsted Laboratory, Niels Bohr Institute, Universitetsparken 5, DK-2100 Copenhagen, Denmark.
Avishai
Y
Kikoin
K