Phonon affected transport through molecular quantum dots

Abstract

To describe the interaction of molecular vibrations with electrons at a quantum dot contacted to metallic leads, we extend an analytical approach that we previously developed for the many-polaron problem. Our scheme is based on an incomplete variational Lang-Firsov transformation, combined with a perturbative calculation of the electron-phonon self-energy in the framework of generalised Matsubara functions. This allows us to describe the system at weak to strong coupling and intermediate to large phonon frequencies. We present results for the quantum dot spectral function and for the kinetic coefficient that characterises the electron transport through the dot. With these results we critically examine the strengths and limitations of our approach, and discuss the properties of the molecular quantum dot in the context of polaron physics. We place particular emphasis on the importance of corrections to the concept of an antiadiabatic dot polaron suggested by the complete Lang-Firsov transformation.

30 pages, 15 figures, revised version including new figures

References in corpus (10)

• Molecular Transport Junctions: Vibrational Effects
• Transport through a molecular quantum dot in the polaron crossover regime
• Chebyshev approach to quantum systems coupled to a bath
• Phonon spectral function of the Holstein polaron
• Spectral functions of the spinless Holstein model
• Localized polarons and doorway vibrons in finite quantum structures
• Optical conductivity of polaronic charge carriers
• Solution of the Holstein polaron anisotropy problem
• Slave boson theory for transport through magnetic molecules with vibronic states
• Bipolaron formation in 1D-3D quantum dots: A lattice quantum Monte Carlo approach

Cited by in corpus (9)

• Non-equilibrium electronic structure of interacting single-molecule nanojunctions: vertex corrections and polarization effects for the electron-vibron coupling
• Non-equilibrium inelastic electronic transport: Polarization effects and vertex corrections to the self-consistent Born approximation
• Non-equilibrium transport through molecular junctions in the quantum regime
• Transport through a vibrating quantum dot: Polaronic effects
• Phonon-affected steady-state transport through molecular quantum dots
• Nanomechanical effects in an Andreev quantum dot
• Chebyshev pseudosite matrix product state approach for the spectral functions of electron-phonon coupling systems
• Exact solution of electronic transport in semiconductors dominated by scattering on polaronic impurities
• Non-equilibrium transport with self-consistent renormalised contacts for a single-molecule nanodevice with electron-vibron interaction