EXCITON DEPHASING IN ZNSE QUANTUM WIRES

The homogeneous linewidths of excitons in wet-etched ZnSe quantum wire s of lateral sizes down to 23 nm are studied by transient four-wave mi xing. The low-density dephasing time is found to increase with decreas ing wire width. This is attributed mainly to a reduction of electron-e xciton scattering within the wire due to the electron trapping in surf ace states and exciton localization. The exciton-exciton scattering ef ficiency, determined by the density dependence of the exciton dephasin g, is found to increase with decreasing win width. This is assigned to the reduced phase space in a quasi-one-dimensional system, enhancing the repulsive interaction between excitons due to Pauli blocking.