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. Results in this model were found consistent with experimental data and sugges...

We investigate the transport fluctuations in both non-relativistic quantum dots and graphene quantum dots with both hyperbolic and nonhyperbolic chaotic scattering dynamics in the classical limit. We find that nonhyperbolic dots generate sharper resonances than those in the hyperbolic case. Strikingly, for the graphene dots, the resonances tend to be much sharper. This means that transmission o...

Motivated by recent advances in fabricating graphene nanostructures, we find that an electron can be trapped in Z-shaped graphene nanoconstriction with zigzag edges. The central section of the constriction operates as a single-level quantum dot, as the current flow towards the adjunct sections (rotated by 60◦) is strongly suppressed due to mismatched valley polarization, although each section i...