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Nonequilibrium charge-Kondo transport through negative-U molecules

Jens Koch·Eran Sela·Yuval Oreg·Felix von Oppen
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Abstract

Low-temperature transport through molecules with effectively negative charging energy U exhibits a charge-Kondo effect. We explore this regime analytically by establishing an exact mapping between the negative-U and the positive-U Anderson models, which is suitable for the description of nonequilibrium transport. We employ this mapping to demonstrate the intimate relation between nonequilibrium tranport in the spin-Kondo and charge-Kondo regimes, and derive analytical expressions for the nonlinear current-voltage chracteristics as well as the shot noise in the latter regime. Applying the mapping in the opposite direction, we elucidate the finding of super-Poissonian noise in the positive-U Anderson model at high temperatures, by relating the correlations between spin flips to pair-tunneling processes at negative U.

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Jens Koch, Eran Sela, Yuval Oreg, Felix von Oppen. 2006-10-26. Nonequilibrium charge-Kondo transport through negative-U molecules. https://doi.org/10.1103/physrevb.75.195402

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