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Excess Kondo resonance in a quantum dot device with normal and superconducting leads: the physics of Andreev-normal co-tunneling

Qing-feng Sun·Hong Guo·Tsung-han Lin
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Abstract

We report on a novel Kondo phenomenon of interacting quantum dots coupled asymmetrically to a normal and a superconducting lead. The effects of intradot Coulomb interaction and Andreev tunneling give rise to Andreev bound resonances. As a result, a new type of co-tunneling process which we term Andreev-normal co-tunneling, is predicted. At low temperatures, coherent superposition of these co-tunneling processes induces a Kondo effect in which Cooper pairs directly participate formation of a spin singlet, leading to four Kondo resonance peaks in the local density of states, and enhancing the tunneling current.

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Qing-feng Sun, Hong Guo, Tsung-han Lin. 2001-10-25. Excess Kondo resonance in a quantum dot device with normal and superconducting leads: the physics of Andreev-normal co-tunneling. https://doi.org/10.1103/physrevlett.87.176601

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