Kondo Effect and dephasing in a hybrid quantum dot-ring coupled to a researvoir

摘要

The persistent current in a hybrid Aliaronov-Bohm ring - quantum dot system coupled to a reservoir is investigated in the spin fluctuation limit. It is shown that the Kondo correlation between the quantum dot and the reservoir induces dephasing in the absence of direct charge transfer. We predict an anomalous nature of this spin-fluctuation induced dephasing which tends to enhance the persistent current. We explain our result in terms of the spin-charge separation. Various aspects of the spin fluctuation induced dephasing are analyzed.