Sökning: "quantum wire"
Visar resultat 1 - 5 av 23 avhandlingar innehållade orden quantum wire.
1. Modelling of Quantum Transport in Nanostructures
Sammanfattning : In this thesis, theoretical studies of the transport properties of three nanoscale systems: one-dimensional (1D) quantum wires (QWRs), zero-dimensional (0D), laterally confined, double-barrier resonant tunnelling structures (DBRTSs) and three-terminal ballistic junctions (TBJs), have been performed. In the first part of the thesis, an overview of the realization and properties of such systems is given along with a description of modelling tools used in the calculations. LÄS MER
2. Transport Studies of Local-Gate Defined Quantum Dots in Nanowires
Sammanfattning : This thesis focuses on electrical transport in semiconductor InAs nanowires grown by chemical beam epitaxy. Initially, transport length scales of homogeneous InAs n-type nanowires are characterized by low-temperature magnetoconductance measurements. The measurements show phase-coherent conductivity corrections. LÄS MER
3. Quantum transport and spin effects in lateral semiconductor nanostructures and graphene
Sammanfattning : This thesis studies electron spin phenomena in lateral semi-conductor quantum dots/anti-dots and electron conductance in graphene nanoribbons by numerical modelling. In paper I we have investigated spin-dependent transport through open quantum dots, i.e., dots strongly coupled to their leads, within the Hubbard model. LÄS MER
4. Quantum Devices from the Assembly of Zero- and One-Dimensional Building Blocks
Sammanfattning : This thesis describes novel methods for the fabrication of nanometer-scale electronic devices, such as single-electron transistors and resonant tunneling diodes, from wire- and dot-shaped building blocks. The first part of the thesis describes the manipulation of metal nanoparticles and carbon nanotubes using an atomic force microscope. LÄS MER
5. Spin splitting in open quantum dots and related systems
Sammanfattning : This thesis addresses electron spin phenomena in semi-conductor quantum dots/anti-dots from a computational perspective. In the first paper (paper I) we have studied spin-dependent transport through open quantum dots, i.e., dots strongly coupled to their leads, within the Hubbard model. LÄS MER