Interaction effects in the transport of particles in nanowire quantum dots
Author
Summary, in English
Interactions between physical bodies constantly affect their properties.
This thesis presents a theoretical study on the effects of interaction in few-body nanowire quantum dots. The focus is to a large extent on a phenomenon called Wigner localization, and how this, as well as other interaction effects, can be identified in an experiment by transport spectroscopy and by thermopower measurements. The physical systems considered are electrons in semiconductor nanowires and an ultracold gas of dipolar particles in magneto-optical traps. The full many-body description of the nanowire quantum dot is obtained by exact diagonalization (also known as the configuration interaction method) while the transport simulations are based on a Pauli master equation approach. The thesis is based on three papers: In Paper I we examine Wigner localization in an InSb nanowire quantum dot and identify the onset of Wigner localization in an experiment. In Paper II we study how different interaction regimes can be accessed in an ultracold dipolar gas by tuning the dipole-dipole interaction externally, providing Wigner localization for strong repulsion and total current blockade for attraction. The effect of excited states on the thermopower lineshape is investigated in Paper III, asserting the possibility to detect the onset of Wigner localization by thermopower measurements.
This thesis presents a theoretical study on the effects of interaction in few-body nanowire quantum dots. The focus is to a large extent on a phenomenon called Wigner localization, and how this, as well as other interaction effects, can be identified in an experiment by transport spectroscopy and by thermopower measurements. The physical systems considered are electrons in semiconductor nanowires and an ultracold gas of dipolar particles in magneto-optical traps. The full many-body description of the nanowire quantum dot is obtained by exact diagonalization (also known as the configuration interaction method) while the transport simulations are based on a Pauli master equation approach. The thesis is based on three papers: In Paper I we examine Wigner localization in an InSb nanowire quantum dot and identify the onset of Wigner localization in an experiment. In Paper II we study how different interaction regimes can be accessed in an ultracold dipolar gas by tuning the dipole-dipole interaction externally, providing Wigner localization for strong repulsion and total current blockade for attraction. The effect of excited states on the thermopower lineshape is investigated in Paper III, asserting the possibility to detect the onset of Wigner localization by thermopower measurements.
Publishing year
2015
Language
English
Full text
Document type
Dissertation
Topic
- Physical Sciences
Keywords
- Wigner localization
- atom transport
- electron transport
- ultracold dipolar gases
- Quantum dots
- semiconductor nanowires
- current blockade
- thermopower
- Fysicumarkivet A:2015:Kristinsdottir
Status
Published
Supervisor
ISBN/ISSN/Other
- ISBN: 978-91-7623-280-4
- ISBN: 978-91-7623-279-8
Defence date
12 May 2015
Defence time
10:15
Defence place
Lundamarksalen at Lund Observatory, Sölvegatan 27, Lund
Opponent
- Peter Schmelcher