1 research outputs found
Nonequilibrium Kondo Effect in a Multi-level Quantum Dot near singlet-triplet transition
The linear and nonlinear transport through a multi-level lateral quantum dot
connected to two leads is investigated using a generalized finite-
slave-boson mean field approach. For a two-level quantum dot, our calculation
demonstrates a substantial conductance enhancement near the degeneracy point of
the spin singlet and triplet states, a non-monotonic temperature-dependence of
conductance and a sharp dip and nonzero bias maximum of the differential
conductance. These agree well with recent experiment observations. This
two-stage Kondo effect in an out-of-equilibrium situation is attributed to the
interference between the two energy levels.Comment: 4 pages, 3 figure