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Kondo-Enhanced Andreev Tunneling in InAs Nanowire Quantum Dots

T. Sand-Jespersen·J. Paaske·B. M. Andersen·K. Grove-Rasmussen·H. I. Jørgensen·M. Aagesen·C. Sørensen·P. E. Lindelof·K. Flensberg·J. Nygård
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Abstract

We report measurements of the nonlinear conductance of InAs nanowire quantum dots coupled to superconducting leads. We observe a clear alternation between odd and even occupation of the dot, with sub-gap-peaks at $|V_{sd}|=Δ/e$ markedly stronger(weaker) than the quasiparticle tunneling peaks at $|V_{sd}|=2Δ/e$ for odd(even) occupation. We attribute the enhanced $Δ$-peak to an interplay between Kondo-correlations and Andreev tunneling in dots with an odd number of spins, and substantiate this interpretation by a poor man's scaling analysis.

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T. Sand-Jespersen, J. Paaske, B. M. Andersen, K. Grove-Rasmussen, H. I. Jørgensen, M. Aagesen, C. Sørensen, P. E. Lindelof, K. Flensberg, J. Nygård. 2007-03-10. Kondo-Enhanced Andreev Tunneling in InAs Nanowire Quantum Dots. https://doi.org/10.1103/physrevlett.99.126603

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