Spin Polarization and Conductance in Quantum Wires under External Bias Potentials
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
We study the spin polarization and conductance in infinitely long quasi one-dimensionalquantum wires under various conditions in an attempt to reproduce and to explain some of theanomalous conductance features as seen in various experiments. In order to accomplish thistask we create an idealized model of a quantum wire in a split-gate semiconductorheterostructure and we perform self-consistent Hartree-Fock calculations to determine theelectron occupation and spin polarization. Based on those results we calculate the currentthrough the wire as well as the direct and differential conductances. In the frame of theproposed model the results show a high degree of similarity to some of the experimentallyobserved conductance features, particularly the 0.25- and 0.85-plateaus. These results lead usto the conclusion that those conductance anomalies are in fact caused by the electronsspontaneously polarizing due to electron-electron interactions when an applied potentialdrives a current through the wire.
Place, publisher, year, edition, pages
2010. , 51 p.
Electron, Spin, Polarization, Quantum, Quantum Wire, GaAs, Gallium Arsenide, Quantization, Conductance
IdentifiersURN: urn:nbn:se:liu:diva-54514ISRN: LITH-IFM-A-EX--10/2224--SEOAI: oai:DiVA.org:liu-54514DiVA: diva2:306054
UppsokPhysics, Chemistry, Mathematics