Excitons in coupledInAs∕InPself-assembled quantum wires

Optical transitions in coupled $\mathrm{In}\mathrm{As}∕\mathrm{In}\mathrm{P}$ self-assembled quantum wires are studied within the single-band effective-mass approximation including effects due to strain. Both vertically and horizontally coupled quantum wires are investigated and the ground state, excited states, and the photoluminescence peak energies are calculated. Where possible, we compare with available photoluminescence data from which it was possible to determine the height of the quantum wires. An anticrossing of the energy of excited states is found for vertically coupled wires signaling a change of symmetry of the exciton wave function. This crossing is the signature of two different coupling regimes.