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Magnus Paulsson

Publications and source records attributed to Magnus Paulsson.

2 recordsLinked to original sources

Inelastic transport through molecules: comparing first-principles calculations to experiments.

We present calculations of the elastic and inelastic conductance through three different hydrocarbon molecules connected to gold electrodes. Our method is based on a combination of the nonequilibrium Green's function method with density functional theory. Vibrational effects in these molecular junctions were previously investigated experimentally by Kushmerick et al. (Nano Lett. 2004, 4, 639). Our results are in good agreement with the measurements and provide insights into (i) which vibrational modes are responsible for inelastic scattering, (ii) the width of the inelastic electron tunneling signals, and (iii) the mechanisms of heating and cooling of the vibrational modes induced by the coupling to the charge carriers.

Alkanes↗

High-field quasiballistic transport in short carbon nanotubes.

Single walled carbon nanotubes with Pd Ohmic contacts and lengths ranging from several microns down to 10 nm are investigated by electron transport experiments and theory. The mean-free path (MFP) for acoustic phonon scattering is estimated to be l(ap) approximately 300 nm, and that for optical phonon scattering is l(op) approximately 15 nm. Transport through very short (approximately 10 nm) nanotubes is free of significant acoustic and optical phonon scattering and thus ballistic and quasiballistic at the low- and high-bias voltage limits, respectively. High currents of up to 70 microA can flow through a short nanotube. Possible mechanisms for the eventual electrical breakdown of short nanotubes at high fields are discussed. The results presented here have important implications to high performance nanotube transistors and interconnects.

Journal Article↗