Vibrational Andreev bound states in magnetic molecules

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.

5 pages, 4 figures

References in corpus (12)

• The numerical renormalization group method for quantum impurity systems
• Inelastic electron tunneling via molecular vibrations in single-molecule transistors
• Franck-Condon blockade in suspended carbon nanotube quantum dots
• Spectral properties of locally correlated electrons in a BCS superconductor
• Many Body Effects on the Transport Properties of Single-Molecule Devices
• Inelastic tunneling effects on noise properties of molecular junctions
• Quantum transport through a deformable molecular transistor
• Effects of charge-dependent vibrational frequencies and anharmonicities in transport through molecules
• Electronic Transport through Magnetic Molecules with Soft Vibrating Modes
• Kondo effect and channel mixing in oscillating molecules
• Electron-Phonon Correlation Effects in Molecular Transistors
• Numerical Renormalization Group Study of Probability Distributions for Local Fluctuations in the Anderson-Holstein and Holstein-Hubbard Models