Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 9: Poster 1
HL 9.82: Poster
Montag, 23. März 2009, 14:30–17:00, P2
Spin-transitions in semiconductor quantum rings — •Benjamin Baxevanis and Daniela Pfannkuche — 1. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, D-20355 Hamburg, Germany
The path integral Monte Carlo (PIMC) method is a numerically exact method to investigate properties of quantum systems in thermal equilibrium which are not in the range of other numerical methods. The main advantage of PIMC is its ability to treat strongly correlated electron systems at finite temperature. Usual approaches preserve only Sz symmetry and result in thermal averages of states with different S2 quantum numbers. In order to avoid this spin contamination problem we extend the PIMC method to study magnetic transitions in a semiconductor quantum ring: using Young diagrams we explicitly construct eigenstates of the S2 operator. In our model of a quantum ring diameter, width and elliptical deformation can be tuned. At a given electron number the ground state exhibits spin-transitions depending on the ring geometry.