Heiss W.D. (ed.) Quantum dots.. a doorway to - tiera.ru

A Guide for the Reader
Quantum dots, often denoted artificial atoms, are the exquisite tools by which
quantum behavior can be probed on a scale appreciably larger than the atomic
scale, that is, on the nanometer scale. In this way, the physics of the devices
is closer to classical physics than that of atomic physics but they are still
sufficiently small to clearly exhibit quantum phenomena. The present volume
is devoted to some of these fascinating aspects.
In the first contribution general theoretical aspects of Fermi liquids are
addressed, in particular, the renormalization group approach. The choice of
appropriate variables as a result of averaging over “unimportant” variables is
presented. This is then aptly applied to large quantum dots. The all important
scales, ballistic dots and chaotic motion are discussed. Nonperturbative
methods and critical phenomena feature in this thorough treatise. The traditional
phenomenological Landau parameters are given a more satisfactory
theoretical underpinning.
A completely different approach is encountered in the second contribution
in that it is a thorough experimental expose of what can be done or expected in
the study of small quantum dots. Here the emphasis lies on the electron spin to
be used as a qubit. The experimental steps toward using a single electron spin –
trapped in a semiconductor quantum dot – as a spin qubit are described.
The introduction contains a resume of quantum computing with quantum
dots. The following sections address experimental implementations, the use
of different quantum dot architectures, measurements, noise, sensitivity and
high-speed performance. The lectures are based on a collaborative effort of
research groups in the Netherlands and in Japan.
The last two contributions are again theoretical in nature and address
particular aspects relating to quantum dots. In the third lecture series, mechanisms
of low-temperature electronic transport through a quantum dot –
weakly coupled to two conducting leads – are reviewed. In this case transport is
dominated by electron–electron interaction. At moderately low temperatures
(comparing with the charging energy) the linear conductance is suppressed by