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Biomedical subjects

A Erbe

Publications and source records attributed to A Erbe.

5 recordsLinked to original sources
PubMed2006

Layer reduction in driven 2D-colloidal systems through microchannels.

The transport behavior of a system of gravitationally driven superparamagnetic colloidal particles is investigated. The motion of the particles through a narrow channel is governed by magnetic dipole interactions, and a layered structure forms parallel to the walls. The arrangement of the particles is perturbed by diffusion and the motion induced by gravity leading to a density gradient along the channel. Our main result is the reduction of the number of layers. Experiments and Brownian dynamics simulations show that this occurs due to the density gradient along the channel.

Journal Article↗
PubMed2004

Single- and multigrain nanojunctions with a self-assembled monolayer of conjugated molecules.

Systematic conductivity measurements in nanoscale junctions containing a self-assembled monolayer of conjugated molecules are reported. Different conductivity mechanisms are identified depending on the granularity of the metal used as a substrate for assembling the monolayer. Unexpectedly, the energy scale controlling the dominant conductance channels is quite low in comparison with the molecular level spacing. In single-grain junctions, the dominant conductance mechanism is hopping with an energy scale of the order of 10-100 meV determined by the nature of the metal contacts. In the case of multigrain junctions, additional tunnel conductance is observed with low-energy Coulomb-blockade features.

Journal Article↗
PubMed2001

Nanomechanical resonator shuttling single electrons at radio frequencies.

We observe transport of electrons through a metallic island on the tip of a nanomechanical pendulum. The resulting tunneling current shows distinct features corresponding to the discrete mechanical eigenfrequencies of the pendulum. We report on measurements covering the temperature range from 300 down to 4.2 K. We explain the I-V curve, which unexpectedly differs from previous theoretical predictions, with model calculations based on a master equation approach.

Journal Article↗