Prediction of inelastic light scattering spectra from electronic collective excitations in GaAs/AlGaAs core-multishell nanowires

Abstract

We predict inelastic light scattering spectra from electron collective excitations in a coaxial quantum well embedded in a core-multishell $\mathrm{GaAs}/\mathrm{AlGaAs}$ nanowire. The complex composition, the hexagonal cross section, and the remote doping of typical samples are explicitly included, and the free electron gas is obtained by a density functional theory (DFT) approach. Inelastic light scattering cross sections due to charge and spin collective excitations belonging to quasi-one-dimensional (1D) and quasi-2D states, which coexist in such radial heterostructures, are predicted in the nonresonant approximation from a fully three-dimensional multisubband time-dependent DFT (TDDFT) formalism. We show that collective excitations can be classified in azimuthal, radial, and longitudinal excitations, according to the associated density fluctuations, and we suggest that their character can be exposed by specific spectral dispersion of inelastic light scattering along different planes of the heterostructure.