Correlation-induced conductance suppression at level degeneracy in a quantum dot

HA Nilsson, O Karlstr�m, M Larsson, P Caroff…�- Physical Review Letters, 2010 - APS
HA Nilsson, O Karlstr�m, M Larsson, P Caroff, JN Pedersen, L Samuelson, A Wacker
Physical Review Letters, 2010APS
The large, level-dependent g factors in an InSb nanowire quantum dot allow for the
occurrence of a variety of level crossings in the dot. While we observe the standard
conductance enhancement in the Coulomb blockade region for aligned levels with different
spins due to the Kondo effect, a vanishing of the conductance is found at the alignment of
levels with equal spins. This conductance suppression appears as a canyon cutting through
the web of direct tunneling lines and an enclosed Coulomb blockade region. In the center of�…
The large, level-dependent factors in an InSb nanowire quantum dot allow for the occurrence of a variety of level crossings in the dot. While we observe the standard conductance enhancement in the Coulomb blockade region for aligned levels with different spins due to the Kondo effect, a vanishing of the conductance is found at the alignment of levels with equal spins. This conductance suppression appears as a canyon cutting through the web of direct tunneling lines and an enclosed Coulomb blockade region. In the center of the Coulomb blockade region, we observe the predicted correlation-induced resonance. Our findings are supported by numerical and analytical calculations.
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