Existence of exciton crystals in quantum wires

An exciton crystal (EC) is predicted in a quasi-one-dimensional (1D) semiconductor quantum wire for the densities (1<${\mathit{r}}_{\mathit{s}}$≤5.5) due to the repulsive interaction between singlet excitons (x’s). Low-lying excitations, stability, and melting of the EC are determined within the Heitler-London approximation. The expected short condensation times (ps) will allow an EC formation in, e.g., GaAs quantum-well wires with relative short x lifetimes. For T≤10 K the EC is a pure quantum crystal which favors collective, coherent emission in the form of superradiance.