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Long range interaction in nanostructures. A one dimensional quantum dot coupled to quantum wires of interacting electrons
T. Kleimann and G. Cuniberti.
Nanotubes & Nanostructures 2000
2000.10; S.Margherita di Pula-Cagliari, Italy
| In recent years considerable progress has been made in
the fabrication of quasi one dimensional
nanostructures. Such quantum wires are ideal tools for
studying the interplay of impurity and interaction
effects. It is even possible to form one dimensional
quantum dots coupled to one channel quantum wires [1]
and probe their transport properties in the linear and
non-linear regime where the latter gives insight in the
spectral properties of the system.
The mutual Coulomb interaction is often treated
phenomenologically - as in classical Coulomb blockade
theory in terms of a capacitance assigned to the dot.
In one dimension however interactions can be accounted
for microscopically by employing bosonisation. Then one
usually resorts to the long wave length zero range
limit of the interaction and can use Luttinger liquid
theory. These treatments disguise effects due to the
long range nature of Coulomb interaction. On the one
hand the microscopic charging energy of the quantum dot
between the links is underestimated in the zero range
interaction. On the other hand one cannot treat leads
and dot as separate systems when the interaction
intermediates through barriers between all parts of the
system. Basically this leads to an ``open'' quantum dot.
We use Luttinger liquid theory and a particular form of
finite range interaction to investigate its impact on
the charging effects and spectral properties of a
system consisting of a double barrier structure in a
quantum wire and compare to the usual zero range
interaction case. We provide a microscopic description
of Coulomb blockade and single electron tunneling and
compare our results with recent experiments.
[1]
O.M. Auslaender et al., Phys. Rev. Lett 84, 1764
(2000).
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Prof. Dr. Gianaurelio Cuniberti
secretariat:
postal address:
Institute for Materials Science
TU Dresden
01062 Dresden, Germany
visitors and courier address:
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