Herbert Schoeller

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We study the Fano-Kondo effect in a closed Aharonov-Bohm (AB) interferometer which contains a single-level quantum dot and predict a frequency doubling of the AB oscillations as a signature of Kondo-correlated states. Using the Keldysh formalism, the Friedel sum rule, and the numerical renormalization group, we calculate the exact zero-temperature linear(More)
We discuss electronic transport through a lateral quantum dot close to the singlet-triplet degeneracy in the case of a single conduction channel per lead. By applying the numerical renormalization group, we obtain rigorous results for the linear conductance and the density of states. A new quantum phase transition of the Kosterlitz-Thouless-type is found,(More)
– We describe single electron tunneling through molecular structures under the influence of nano-mechanical excitations. We develop a full quantum mechanical model, which includes charging effects and dissipation, and apply it to the vibrating C60 single electron transistor experiment by Park et al. [Nature 407, 57 (2000)]. We find good agreement and argue(More)
We review recent progress in the theoretical description of correlation and quantum fluctuation phenomena in charge transport through single molecules, quantum dots and quantum wires. Various physical phenomena are addressed, relating to cotunneling, pair-tunneling, adiabatic quantum pumping, charge and spin fluctuations, and inhomogeneous Luttinger(More)
We demonstrate that in a single molecule magnet strongly coupled to electrodes the Kondo effect involves all magnetic excitations. This Kondo effect is induced by the quantum tunneling of the magnetic moment. Importantly, the Kondo temperature TK can be much larger than the magnetic splittings. We find a strong modulation of the Kondo effect as a function(More)
We consider transport through a single-molecule magnet strongly coupled to metallic electrodes. We demonstrate that, for a half-integer spin of the molecule, electron and spin tunneling cooperate to produce both quantum tunneling of the magnetic moment and a Kondo effect in the linear conductance. The Kondo temperature depends sensitively on the ratio of(More)
The influence of high-frequency fields on quantum transport through a quantum dot is studied in the low-temperature regime. We generalize the non crossing approximation for the infinite-U Anderson model to the timedependent case. The dc spectral density shows asymmetric Kondo side peaks due to photon-assisted resonant tunneling. As a consequence we predict(More)