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arXiv · 1205.1957

Vibrational Andreev bound states in magnetic molecules

Denis Golez·Janez Bonca·Rok Zitko
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Abstract

We predict the existence of vibrational Andreev bound states in deformable magnetic molecules on superconducting surfaces. We discuss the Anderson impurity model with electron-phonon coupling to a realistic anharmonic vibrational mode that modulates the tunneling barrier and show that the vibronic features are spectroscopically most visibile near the transition point between the Kondo-screened singlet and the unscreened doublet ground state. We find competing tendencies between phonon hardening due to anharmonicity and softening due to coupling to electrons, contrary to the Anderson-Holstein model and other models with harmonic local phonon mode where the vibrational mode is always softened. In addition, we find that the singlet and doublet many-body states may experience very different effective phonon potentials.

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Denis Golez, Janez Bonca, Rok Zitko. 2012-05-09. Vibrational Andreev bound states in magnetic molecules. https://doi.org/10.1103/physrevb.86.085142

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