Resonant inelastic light scattering by electronic excitations in tunable quantum wire structures

Resonant inelastic light scattering was used to investigate both charge density excitations and spin density excitations in shallow etched GaAs/AlGaAs quantum wires. A semi-transparent Schottky gate was evaporated on top of the samples which allowed a strong tunability of the electron density and the lateral confinement, even under high illumination conditions used for inelastic light scattering. The range of charge density excitations extended from confined plasmons to a plasmon band structure. Both intra- and intersubband single-particle excitations were observed. The occurrence of a tunable doublet structure in depolarized plane wave spectra is attributed to spin flip intrasubband single-particle excitations.