2011/05/31 by T. Koch, Thomas Koch, J. Loos +4 · 30 citations
Engineering · Physics and Astronomy · #Adiabatic process #Condensed matter physics #Electron #Inelastic electron tunneling spectroscopy #Molecular Junctions and Nanostructures #Non-equilibrium thermodynamics #Phonon #Physics #Polaron #Quantum #Quantum and electron transport phenomena #Quantum mechanics #Quantum tunnelling #Renormalization #Semiconductor Quantum Structures and Devices #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.84.125131
published in Physical Review B 84(12) (American Physical Society) · 18 pages, 7 figures, final version
arxiv created 2011/09/20 · openalex publication_date 2011/09/20 · arxiv updated 2015/05/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We consider a quantum dot, affected by a local vibrational mode and contacted to macroscopic leads, in the nonequilibrium 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 a 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 antiadiabatic phonon frequencies and weak to strong electron-phonon couplings. We investigate the qualitative impact of the quasiparticle 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.