Kondo effect in multielectron quantum dots at high magnetic fields - art. no. 035319

We present a general description of low-temperature transport through a qua ntum dot with any number of electrons at filling factor 1<<nu><2. We provid e a general description of a Kondo effect that is turned on by application of an appropriate magnetic field. The spin-flip scattering of carriers by t he quantum dot only involves two, states of the scatterer that may have a l arge spin. This process is described by spin-flip Hubbard operators, which change the angular momentum, leading to a Kondo Hamiltonian. We obtain anti ferromagnetic exchange couplings depending on tunneling amplitudes and corr elation effects. Since Kondo temperature has an exponential dependence on e xchange couplings, quantitative variations of the parameters in different r egimes have important experimental consequences. In particular, we discuss the chessboard aspect of the experimental conductance when represented in a gray scale as a function of both the magnetic field and the gate potential affecting the quantum dot.