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arXiv · 1105.0576

Non-equilibrium transport through molecular junctions in the quantum regime

T. Koch·J. Loos·A. Alvermann·H. Fehske
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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.

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T. Koch, J. Loos, A. Alvermann, H. Fehske. 2011-05-03. Non-equilibrium transport through molecular junctions in the quantum regime. https://doi.org/10.1103/physrevb.84.125131

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