Strained quantum rings

Electronic structures of quantum rings strongly depend on the strain profiles caused by the material environment around the ring. We will investigate the strain distributions and electronic structures of quantum rings capped by a support material of which lattice constant is smaller than those of the substrate and active material, and compare the results with a conventional quantum ring. The support material considerably weakens the longitudinal strains and biaxial strain of quantum rings as well as the hole confinement potentials. The unique band alignment of the structure enables the coexistence of type-I and type-II band alignments.