Internal transitions of negatively charged magneto-excitons and many body effects in a two-dimensional electron gas

Abstract

Spin-singlet and spin-triplet internal transitions of quasi-two-dimensional, negatively charged magneto-excitons (X-) and their evolution with excess electron density have been studied in GaAs/AlGaAs quantum-wells by optically detected resonance (ODR) spectroscopy. In the dilute electron limit, due to magnetic translational invariance, the ODR spectra are dominated by bound-to-continuum bands in contrast to the superficially similar negatively-charged-donor system D-, which exhibits strictly bound-to-bound transitions. With increasing excess electron density in the wells in the magnetic field region corresponding to Landau level filling factors nu < 2 the X- like transitions are blue-shifted; they are absent for nu > 2. The blue-shifted transitions are explained in terms of a new type of collective excitation -- magnetoplasmons bound to a mobile valence band hole, which demonstrates the many-body nature of "exciton-like" magnetoluminescence for nu < 2.

11 pages + 3 figures, final version accepted in PRL

Cited by in corpus (8)

• Definitive observation of the dark triplet ground state of charged excitons in high magnetic fields
• Shake-up Processes in a Low-Density Two-Dimensional Electron Gas: Spin-Dependent Transitions to Higher Hole Landau Levels
• Resonant Enhancement of Inelastic Light Scattering in the Fractional Quantum Hall Regime at $\nu =1/3$
• Electron cyclotron mass in undoped CdTe/CdMnTe quantum wells
• Symmetry Content and Observation of Charged Collective Excitations for Graphene in Strong Magnetic Fields
• Internal transitions of quasi-2D charged magneto-excitons in the presence of purposely introduced weak lateral potential energy variations
• Shake-up Processes in Intersubband Magneto-photoabsorption of a Two-Dimensional Electron Gas
• Internal transitions of negatively charged magnetoexcitons in quantum dots