Fork stamping of pristine carbon nanotubes onto ferromagnetic contacts for spin-valve devices

We present a fabrication scheme called 'fork stamping' optimized for the dry transfer of individual pristine carbon nanotubes (CNTs) onto ferromagnetic contact electrodes fabricated by standard lithography. We demonstrate the detailed recipes for a residue-free device fabrication and in-situ current annealing on suspended CNT spin-valve devices with ferromagnetic Permalloy (Py) contacts and report preliminary transport characterization and magnetoresistance experiments at cryogenic temperatures. This scheme can directly be used to implement more complex device structures, including multiple gates or superconducting contacts.Comment: 7 pages, 4 figures, submitted to IWEPNM 2015 conference proceedings (physica status solidi (b)

Clean carbon nanotubes coupled to superconducting impedance-matching circuits.

Coupling carbon nanotube devices to microwave circuits offers a significant increase in bandwidth (BW) and signal-to-noise ratio. These facilitate fast non-invasive readouts important for quantum information processing, shot noise and correlation measurements. However, creation of a device that unites a low-disorder nanotube with a low-loss microwave resonator has so far remained a challenge, due to fabrication incompatibility of one with the other. Employing a mechanical transfer method, we successfully couple a nanotube to a gigahertz superconducting matching circuit and thereby retain pristine transport characteristics such as the control over formation of, and coupling strengths between, the quantum dots. Resonance response to changes in conductance and susceptance further enables quantitative parameter extraction. The achieved near matching is a step forward promising high-BW noise correlation measurements on high impedance devices such as quantum dot circuits.We acknowledge financial support by the ERC project QUEST, the EC project SE2ND, the NCCR QSIT and the Swiss National Science Foundation.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ncomms816

A micropatterning approach to study the influence of actin cytoskeletal organization on polystyrene nanoparticle uptake by BeWo cells

The microcontact printing technique was successfully applied to study nanoparticle uptake in dependence on different actin cytoskeletal organizations.</p

Tilted-view transmission electron microscopy-access for chirality assignment to carbon nanotubes integrated in MEMS

AbstractFront side etching in combination with sample tilting – instead of wafer through etching – allows for transmission electron microscopy (TEM) investigations on nanostructures integrated in microelectromechanical systems (MEMS). We present electron diffraction (ED) of an individual single-walled carbon nanotube (SWNT) suspended between sharp polysilicon tips on the bulk of a MEMS chip. This novel approach for transmission beam characterization avoids complex wafer backside processing while allowing for chirality assignment to the integrated functional SWNT, as demonstrated here