Accessing the quantum world through electronic transport in carbon nanotubes

In this thesis we will focus on
(a) superconducting electrodes attached to carbon nanotube quantum dots in
order to study the effects of superconducting correlations on quantum systems
and
(b) local gate control of carbon nanotubes in order to define and control double
quantum dot systems in carbon nanotubes. As it turns out, local gates are
an important tool for increasing the control over quantum states in nanotubes.
The thesis is structured as follows:
• Chapter 1 gives a brief introduction to the chemical and electronic properties
of carbon nanotubes and the experimental procedures necessary for
manufacturing electrical devices with single carbon nanotubes.
• In Chapter 2 selected topics of charge transport in mesoscopic systems,
such as single and coupled quantum dots, are reviewed.
• In Chapter 3 we present electrical transport measurements through a carbon
nanotube coupled to a normal and a superconducting lead - a test
system for the exploration of the nature of many-particle correlations.
• Chapter 4 describes how to achieve local gate control over semiconducting
carbon nanotubes by adding top-gate electrodes.
• In Chapter 5 double quantum dots are defined and controlled inside a
carbon nanotube. The system allows for the observation of molecular
states induced by a large tunnel coupling of the dots; an artificial molecule
is defined inside a real one.