Carbon nanotube-based superconducting and ferromagnetic hybrid systems

Carbon nanotube-based superconducting and ferromagnetic hybrid systems

Man, H.T.

Klapwijk, T.M. (promotor)
Morpurgo, A.F. (promotor)

Applied Sciences

2006-09-12

Carbon Nanotubes are molecules with exceptional physical properties that are most useful for applications in the growing field of nanotechnology. In addition, because of its special electrical properties, they are extremely useful for experiments on the fundamental properties of one-dimensional electronic systems. This thesis describes a series of experiments and a short numerical study aimed at a further understanding of the low-temperature electrical transport of single-walled carbon nanotubes. In this work we perform the first experimental study on the effect of quantum interference in single-wall nanotubes in the presence of disorder, leading to the observation of a weak localization effect and conductance fluctuations. Shifting the focus to systems with superconducting or ferromagnetic contacts, we first propose a phenomenological model to describe the experimental results from a former study with superconducting contacts. We also contact single-wall nanotubes with the large-gap superconductor NbTiN to study the rich interplay between Coulomb blockade, level quantization and superconductivity. And finally, the experimental study of nanotubes with highly transparent ferromagnetic contacts shows that the spin-dependent magnetoresistance is due to quantum interference.

carbon nanotube
weak localization
universal conductance fluctuation
andreev reflection
electron-electron interaction
superconductor
spin transport

http://resolver.tudelft.nl/uuid:1cb28f63-d54e-46d0-bd49-d7d87e87083b

978-90-8593-015-0

Institutional Repository

doctoral thesis

(c) 2006 H.T. Man