Symmetry and spin polarization in single and coupled quantum dots - art. no. 165309

We conducted theoretical investigation into the effect of spontaneous elect ron spin polarization in single and coupled quantum dots formed by lateral confinement of a high-mobility two-dimensional electron gas in a semiconduc tor heterostructure. The equilibrium properties of realistic many-electron quantum-dot devices are first studied within the two-dimensional Thomas-Fer mi approximation taking into account contributions from the patterned gate, doping, surface states, and mirror charges. In order to explore spin-depen dent phenomena, a self-consistent model has been developed using the Kohn-S ham local spin-density formalism. We have tested the contribution of electr on correlation in the systems considered and found that it plays a minor ro le, hence only exchange interactions are included in the model. We investig ate the possibilities of manipulating the magnetization (spin polarization) of single and double quantum dots by means of their mutual coupling and sy mmetry breaking caused by variations in the geometry of the gate.