Laterally Squeezed Excitonic Wave Function in Quantum Wires

Abstract

Photoluminescence spectra are systematically studied at 4.2 K on a series of high-quality T-shaped edge quantum wires (QWRs) whose linewidths are as small as 4--7 meV. By measuring spectra in magnetic fields up to 12 T and comparing them with those of quantum wells (QWs), the effect of lateral confinement on exciton wave functions in QWRs is clearly and quantitatively demonstrated. It is found in QWRs formed by intersecting 5 nm thick GaAs QWs that the wave function of a one-dimensional (1D) exciton is squeezed far below the minimum size that has ever been realized by any 2D excitons in GaAs QWs.