Non-equilibrium transport through molecular junctions in the quantum regime

Abstract

We consider a quantum dot, affected by a local vibrational mode and contacted to macroscopic leads, in the non-equilibrium steady-state regime. We apply a variational Lang-Firsov transformation and solve the equations of motion of the Green functions in the Kadanoff-Baym formalism up to second order in the interaction coefficients. The variational determination of the transformation parameter through minimization of the thermodynamic potential allows us to calculate the electron/polaron spectral function and conductance for adiabatic to anti-adiabatic phonon frequencies and weak to strong electron-phonon couplings. We investigate the qualitative impact of the quasi-particle renormalization on the inelastic electron tunneling spectroscopy signatures and discuss the possibility of a polaron induced negative differential conductance. In the high-voltage regime we find that the polaron level follows the lead chemical potential to enhance resonant transport.

18 pages, 7 figures, final version

References in corpus (10)

• Molecular Transport Junctions: Vibrational Effects
• Franck-Condon blockade and giant Fano factors in transport through single molecules
• Non-linear response of molecular junctions: The polaron model revisited
• Phonon Driven Nonlinear Electrical Behavior in Molecular Devices
• Chebyshev approach to quantum systems coupled to a bath
• Spectral functions of the spinless Holstein model
• Localized polarons and doorway vibrons in finite quantum structures
• Insulator-metal transition in biased finite polyyne systems
• Optical conductivity of polaronic charge carriers
• Transport through a vibrating quantum dot: Polaronic effects

Cited by in corpus (16)

• Influence of vibrational modes on the quantum transport through a nano-device
• Effects of electron-phonon interaction on thermal and electrical transport through molecular nano-conductors
• Functional renormalization group study of the Anderson--Holstein model
• Thermoelectric effects in molecular quantum dots with contacts
• Nonequilibrium thermoelectric transport through vibrating molecular quantum dots
• Thermoelectric transport through a quantum nanoelectromechanical system and its backaction
• Influence of phonon-assisted tunneling on the linear thermoelectric transport through molecular quantum dots
• Effective-Hamiltonian theory: An approximation to the equilibrium state of open quantum systems
• Nonequilibrium distribution functions for quantum transport: universality and approximation for the steady state regime
• Exponential and power-law renormalization in phonon-assisted tunneling
• Negative differential conductance in molecular junctions: an overview of experiment and theory
• Phonon-affected steady-state transport through molecular quantum dots
• Local density of states on a vibrational quantum dot out of equilibrium
• Finite-bias transport through the interacting resonant level model coupled to a phonon mode -- a functional renormalization group study
• Quantum transport through a molecular level: a scattering states numerical renormalisation group study
• Heating and thermoelectric transport in a molecular junction