Phonon-assisted tunneling and two-channel Kondo physics in molecular junctions
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.
Cite
@article{arxiv.0902.3225,
title = {Phonon-assisted tunneling and two-channel Kondo physics in molecular junctions},
author = {Luis G. Dias da Silva and Elbio Dagotto},
journal= {arXiv preprint arXiv:0902.3225},
year = {2009}
}
Comments
5 pages, 4 figures; to appear in Phys. Rev. B