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arXiv · 0902.3225

Phonon-assisted tunneling and two-channel Kondo physics in molecular junctions

Luis G. Dias da Silva·Elbio Dagotto
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Abstract

The interplay between vibrational modes and Kondo physics is a fundamental aspect of transport properties of correlated molecular conductors. We present theoretical results for a single molecule in the Kondo regime connected to left and right metallic leads, creating the usual coupling to a conduction channel with left-right parity ("even"). A center-of-mass vibrational mode introduces an additional, phonon-assisted, tunneling through the antisymmetric ("odd") channel. A non-Fermi liquid fixed point, reminiscent of the two-channel Kondo effect, appears at a critical value of the phonon-mediated coupling strength. Our numerical renormalization-group calculations for this system reveal non-Fermi-liquid behavior at low temperatures over lines of critical points. Signatures of this strongly correlated state are prominent in the thermodynamic properties and in the linear conductance.

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Luis G. Dias da Silva, Elbio Dagotto. 2009-02-20. Phonon-assisted tunneling and two-channel Kondo physics in molecular junctions. https://doi.org/10.1103/physrevb.79.155302

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