GaAs/${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As quantum-well wires with lateral dimensions of 70 nm have been prepared by mesa etching of 14-nm-wide quantum-well systems. In photoluminescence excitation two heavy-hole (hh) exciton transitions, ${\mathrm{hh}}_{11}$ and ${\mathrm{hh}}_{12}$, separated by 2.5 meV, were observed. These transitions result from 1D quantum-confined energy states in the narrow wires. The 1D character was reflected in a strong polarization dependence and in a unique magnetic field behavior indicating an enhancement of the excitonic interaction of the 1D ground state by about 15%.

• Received 8 June 1989

DOI:https://doi.org/10.1103/PhysRevLett.63.2124