FERMI-EDGE SINGULARITIES IN INGAAS AND GAAS QUANTUM WIRES

Strong Fermi-edge singularities (FES) were observed in the magnetolumi nescence spectra of InGaAs quantum wires of electronic widths of L(ww) almost-equal-to 500 angstrom. These quasi-1-dimensional (1D) many-ele ctron/one-hole correlation effects cause a large shift in spectral wei ght from the band-edge to the conduction Fermi energy, when compared w ith unpatterned (2D) structures. While the FES effects in the InGaAs q uantum wires are associated with spatially direct transitions, we have also observed related effects in GaAs, where a Schottky gate bias is needed to induce the effect due to the dominantly spatially indirect n ature of the transitions.