Optical emission of a one-dimensional electron gas in semiconductor V-shaped quantum wires

The optical emission spectrum of a one-dimensional electron gas has been studied in modulation-doped GaAs quantum wires grown by molecular-beam epitaxy on V-grooved substrates. At low temperatures the spectra are dominated by a strong Fermi-edge singularity, as in previously reported results for ion-milled quantum wires. The emission spectral shape and its temperature dependence are identical for both sets of wires, revealing a kind of universal behavior. Comparison with calculations based on the Fermi-liquid model indicate a significant coupling between the electron system and empty conduction subbands.