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Conductance of a molecular wire attached to nanotube electrodes: coupling effects
G. Cuniberti , G. Fagas, and K. Richter.
Nanotubes & Nanostructures 2000
2000.10; S. Margherita di Pula-Cagliari, Italy
| Recent experimental achievements of conductance
measurements through single molecules have initiated
novel research directions in the solid state physics at
the nanometer scale, with molecular electronics as a
forefront. Apart from its great potential for applied
and industrial research, molecular electronics also
poses a wealth of challenges to basic research. Direct
efforts are needed to comprehend the conduction
mechanisms in molecular and supramolecular systems. One
of the main issues deserving more intense
investigations is the role of the coupling between
molecules and nanoleads in contrast to the usually
adopted bulky electrodes. On the other hand studies on
the electronic properties of carbon nanotubes suggest
their promising utilization as wiring elements of
molecular circuits. Therefore, we address the problem
of electron transport across a system consisting of a
molecular wire attached to two semi-infinite carbon
nanotubes. Within the Landauer scattering matrix
approach combined with a recursive Green function
technique for tight binding electrons, we obtain the
conductance as a function of system parameters such as
the coupling strength, and the contact geometry. The
conductance exhibits markedly different behaviors for
the two limiting scenarios of a single contact and a
multiple contact between the wire and the nanotube
interfacial atoms. In particular, the latter
configuration supports a single channel transport,
exhibits a scaling law for the conductance as a
function of the coupling strength and tube diameter,
and manifests a counter intuitive enhancement of the
conductance when the coupling becomes weaker.
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last modified: 2021.03.17 Wed
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Prof. Dr. Gianaurelio Cuniberti
secretariat:
postal address:
Institute for Materials Science
TU Dresden
01062 Dresden, Germany
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