Effect of broadening in the weak-coupling limit of vibrationally coupled electron transport through molecular junctions and the analogy to quantum dot circuit QED systems

2015/03/31 by R. Härtle, Rainer Härtle, Manas Kulkarni · 26 citations
Chemistry · Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Atomic physics #Chemistry #Condensed matter physics #Coupling (piping) #Degrees of freedom (physics and chemistry) #Electron #Electron transport chain #Excitation #Materials science #Microwave #Molecular Junctions and Nanostructures #Molecular vibration #Molecule #Non-equilibrium thermodynamics #Photon #Physics #Population #Quantum and electron transport phenomena #Quantum dot #Quantum mechanics #cond-mat.mes-hall

paper · pdf · doi:10.1103/physrevb.91.245429

published in Physical Review B 91(24) (American Physical Society) · 26 pages, 7 figures; revised version, including a section on the effect of a thermal heat bath

arxiv created 2015/06/15 · openalex publication_date 2015/06/22 · arxiv updated 2015/06/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We investigate the nonequilibrium population of a vibrational mode in the steady state of a biased molecular junction, using a rate equation approach. We focus on the limit of weak electronic-vibrational coupling and show that, in the resonant transport regime and for sufficiently high bias voltages, the level of vibrational excitation increases with decreasing coupling strength, assuming a finite and nonzero value. An analytic behavior with respect to the electronic-vibrational coupling strength is only observed if the influence of environmental degrees of freedom is explicitly taken into account. We consider the influence of three different types of broadening: hybridization with the electrodes, thermal fluctuations, and the coupling to a thermal heat bath. Our results apply to vibrationally coupled electron transport through molecular junctions but also to quantum dots coupled to a microwave cavity, where the photon number can be expected to exhibit a similar behavior.

Citations

• Kramers problem for nonequilibrium current-induced chemical reactions
• Charge transfer statistics of a molecular quantum dot with a vibrational degree of freedom
• Vacuum Rabi splitting with a single quantum dot in a photonic crystal nanocavity.
• Effects of charge-dependent vibrational frequencies and anharmonicities in transport through molecules
• Theory of vibrationally inelastic electron transport through molecular bridges
• Inelastic Scattering and Local Heating in Atomic Gold Wires
• Inelastic Electron Tunneling via Molecular Vibrations in Single-Molecule Transistors
• Theory of vibrational absorption sidebands in the Coulomb-blockade regime of single-molecule transistors
• Manipulating quantum entanglement with atoms and photons in a cavity
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• Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamics
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• Strong coupling in a single quantum dot–semiconductor microcavity system