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We study the influence of laser radiation on the electron transport through a molecular wire weakly coupled to two leads. In the absence of a generalized parity symmetry, the molecule rectifies the laser induced current, resulting in…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Jörg Lehmann , Sigmund Kohler , Peter Hänggi , Abraham Nitzan

The influence of an electron-vibrational coupling on the laser control of electron transport through a molecular wire that is attached to several electronic leads is investigated. These molecular vibrational modes induce an effective…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Jörg Lehmann , Sigmund Kohler , Volkhard May , Peter Hänggi

A molecular wire coupled to two electron reservoirs is investigated within a tight-binding approach including spin and Coulomb interaction. Under the assumption of weak coupling to the electron reservoirs a quantum master equation can be…

Mesoscale and Nanoscale Physics · Physics 2007-08-28 Ulrich Kleinekathoefer , GuangQi Li , Sven Welack , Michael Schreiber

We introduce a theoretical approach based on scattering theory and total energy methods that treats transport non-linearities, conformational changes and charging effects in molecular wires in a unified way. We apply this approach to…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Eldon Emberly , George Kirczenow

We investigate transport through molecular wires whose energy levels are affected by environmental fluctuations. We assume that the relevant fluctuations are so slow that they, within a tight-binding description, can be described by…

Mesoscale and Nanoscale Physics · Physics 2008-07-09 Franz J. Kaiser , Peter Hänggi , Sigmund Kohler

We investigate a one-dimensional electron liquid with two point scatterers of different strength. In the presence of electron interactions, the nonlinear conductance is shown to depend on the current direction. The resulting asymmetry of…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 D. E. Feldman , S. Scheidl , V. M. Vinokur

We investigate the possibility of optical current control through single molecules which are weakly coupled to leads. A master equation approach for the transport through a molecule is combined with a Floquet theory for the time-dependent…

Chemical Physics · Physics 2016-09-08 Jörg Lehmann , Sébastien Camalet , Sigmund Kohler , Peter Hänggi

The influence of Gaussian laser pulses on the transport through molecular wires is investigated within a tight-binding model for spinless electrons including correlation. Motivated by the phenomenon of coherent destruction of tunneling for…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Ulrich Kleinekathoefer , GuangQi Li , Sven Welack , Michael Schreiber

The electron tunneling through a molecular junction modeled by a single site weakly coupled to two leads is studied in the presence of a time-dependent external field using a master equation approach. In the case of small bias voltages and…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Guangqi Li , Michael Schreiber , Ulrich Kleinekathoefer

New features of molecular wires can be observed when they are irradiated by laser fields. These effects can be achieved by periodically oscillating fields but also by short laser pulses. The theoretical foundation used for these…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Sven Welack , Michael Schreiber , Ulrich Kleinekathoefer

We calculate non-perturbatively the inelastic effects on the conductance through a conjugated molecular wire-metal heterojunction, including realistic electron-phonon coupling. We show that at sub-band-gap energies the current is dominated…

Materials Science · Physics 2009-10-31 H. Ness , A. J. Fisher

A minimal model for coherent transport through a donor/acceptor molecular junction is presented. The two donor and acceptor sites are described by single levels energetically separated by an intramolecular tunnel barrier. In the limit of…

Disordered Systems and Neural Networks · Physics 2009-11-11 Florian Pump , Gianaurelio Cuniberti

Combining the features of molecular wires and femtosecond laser pulses gives the unique opportunity to optically switch electron currents in molecular devices with very high speed. Based on a weak-coupling approximation between wire and…

Mesoscale and Nanoscale Physics · Physics 2007-08-22 GuangQi Li , Sven Welack , Michael Schreiber , Ulrich Kleinekathoefer

We propose to use a quantum ratchet to transport quantum information in a chain of atoms trapped in an optical superlattice. The quantum ratchet is created by a continuous modulation of the optical superlattice which is periodic in time and…

Quantum Physics · Physics 2007-11-08 Oriol Romero-Isart , Juan Jose Garcia-Ripoll

The realization of a directed current for a quantum particle in a flashing asymmetric potential is studied. It is found that a positive current, i.e. in the direction expected for a conventional diffusive ratchet, can be attained at short…

Other Condensed Matter · Physics 2009-11-10 Emil Lundh , Mats Wallin

We have measured a quantum ratchet effect for vortices moving in a quasi-one-dimensional Josephson junction array. In this solid-state device the shape of the vortex potential energy, and consequently the band structure, can be accurately…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 J. B. Majer , J. Peguiron , M. Grifoni , M. Tusveld , J. E. Mooij

We derive a master equation for the electron transport through molecular wires in the limit of strong Coulomb repulsion. This approach is applied to two typical situations: First, we study transport through an open conduction channel for…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Franz J. Kaiser , Michael Strass , Sigmund Kohler , Peter Hänggi

The treatment of the previous paper is extended to molecular wires. Specifically, the effect of electron-vibrational interactions on the electronic transport induced by femtosecond $\omega+2\omega$ laser fields along unbiased molecular…

Quantum Physics · Physics 2009-11-13 Ignacio Franco , Moshe Shapiro , Paul Brumer

We study coherent backscattering of a quasi-monochromatic laser by a dilute gas of cold two-level atoms. We consider the perturbative regime of weak intensities, where nonlinear effects arise from {\em inelastic} two-photon scattering…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 T. Wellens , B. Gremaud , D. Delande , C. Miniatura

We study the conductance of a quantum wire in the presence of weak electron-electron scattering. In a sufficiently long wire the scattering leads to full equilibration of the electron distribution function in the frame moving with the…

Mesoscale and Nanoscale Physics · Physics 2009-03-19 J. Rech , T. Micklitz , K. A. Matveev
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