From Quantum Dots to Quantum Dashes: Excitonic Spectra of Highly Elongated InAs/InP Nanostructures

摘要: A transition from a cylindrical quantum dot to highly elongated dash is theoretically studied here with an atomistic approach combining empirical tight binding for single particle states and configuration interaction method excitonic properties. Large nanostructure shape anisotropy leads peculiar trend of the bright exciton splitting, which at certain point quenched further elongation, contradicting predictions simplified models. Moreover strong elongation promotes pronounced optical activity dark exciton, that can reach substantial $1\%$ fraction intensity without application any external fields. An calculation augmented elementary phenomenological model expressed in terms light-hole add-mixture increasing deformation. Finally, exctionic complexes $X^-$, $X^+$, $XX$ are as well correlations due presence higher excited identified key-factor affecting energies fine structure.