Periodic exciton-polariton solitons in semiconductor nanowires

Exciton-polariton solitons are nonlinear quasiparticles composed of exciton-photon bound states due to the interaction of light with matter. In semiconductor micro-cavity systems, such as semiconductor micro and nanowires, polaritons are characterized by a negative mass which, combined with the repulsive nonlinear exciton-exciton interaction, leads to the generation of bright polariton solitons. In this work, we investigate the dynamics of bright exciton-polariton solitons in a finite-sized microcavity waveguide, assuming radiative losses to be balanced by the external pumping. Bright-soliton solutions to the model equations of motion, which consist of a periodic train of polariton pulses, are obtained in terms of Jacobi elliptic functions. Analytical expressions of the energies of both photonic and excitonic components of the pulse train are found. Results suggest that the size of a nanowire waveguide plays a relevant role in the quantitative estimate of the energy conveyed by polariton solitons propagating in the medium.