Interaction effects in the transport of particles in nanowire quantum dots

• 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.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Keyword

Wigner localization

atom transport

electron transport

ultracold dipolar gases

Quantum dots

semiconductor nanowires

current blockade

thermopower

Fysicumarkivet A:2015:Kristinsdottir

Publication and Content Type

dok (subject category)

vet (subject category)