Transport properties of a molecule embedded in an Aharonov-Bohm interferometer

Abstract

We theoretically investigate the transport properties of a molecule embedded in one arm of a mesoscopic Aharonov-Bohm interferometer. Due to the presence of phonons the molecule level position (${\epsilon }_d$) and the electron-electron interaction ($U$) undergo a \emph{polaronic shift} which affects dramatically the electronic transport through the molecular junction. When the electron-phonon interaction is weak the linear conductance presents Fano-line shapes as long as the direct channel between the electrodes is opened. The observed Fano resonances in the linear conductance are originated from the interference between the spin Kondo state and the direct path. For strong enough electron-phonon interaction, the electron-electron interaction is renormalized towards negative values, {\it i.e.} becomes effectively attractive. This scenario favors fluctuations between the empty and doubly occupied charge states and therefore promotes a charge Kondo effect. However, the direct path between the contacts breaks the electron-hole symmetry which can efficiently suppress this charge Kondo effect. Nevertheless, we show that a proper tuning of the gate voltage is able to revive the Kondo resonance. Our results are obtained by using the Numerical Renormalization approximation to compute the electronic spectral function and the linear conductance.

17 pages, 12 figures

References in corpus (22)

• A tunable carbon nanotube electromechanical oscillator
• Molecular Transport Junctions: Vibrational Effects
• Coupling of Spin and Orbital Motion of Electrons in Carbon Nanotubes
• Franck-Condon blockade and giant Fano factors in transport through single molecules
• Phonon effects in molecular transistors: Quantum and classical treatment
• Quantum supercurrent transistors in carbon nanotubes
• The Kondo effect in C${}_{60}$ single-molecule transistors
• Electrical generation and absorption of phonons in carbon nanotubes
• Franck-Condon blockade in suspended carbon nanotube quantum dots
• Energy resolution and discretization artefacts in the numerical renormalization group
• Vibrational sidebands and dissipative tunneling in molecular transistors
• Tunneling in suspended carbon nanotubes assisted by longitudinal phonons
• Many Body Effects on the Transport Properties of Single-Molecule Devices
• Vibrational Sidebands and Kondo-effect in Molecular Transistors
• Universal features of electron-phonon interactions in atomic wires
• Pumping of vibrational excitations in a Coulomb blockaded suspended carbon nanotube
• Quantum transport through a deformable molecular transistor
• Electronic Transport through Magnetic Molecules with Soft Vibrating Modes
• Flux-dependent Kondo temperature in an Aharonov-Bohm interferometer with an in-line quantum dot
• Interpolative approach for electron-electron and electron-phonon interactions: from the Kondo to the polaronic regime
• Measuring the Kondo effect in the Aharonov-Bohm interferometer
• Pair Tunneling and shot noise through a single molecule in a strong electron-phonon coupling

Cited by in corpus (3)

• Fano-Kondo resonance versus Kondo plateau in an Aharonov-Bohm ring with an embedded quantum dot
• Bipolaronic blockade effect in quantum dots with negative charging energy
• Charge-Kondo effect mediated by repulsive interactions