Emulation of lossless exciton-polariton condensates by dual-core optical waveguides: Stability, collective modes, and dark solitons
arXiv:1409.2346 · doi:10.1103/PhysRevE.90.043202
Abstract
We propose a possibility to simulate the exciton-polariton (EP) system in the lossless limit, which is not currently available in semiconductor microcavities, by means of a simple optical dual-core waveguide, with one core carrying the nonlinearity and operating close to the zero-group-velocity-dispersion (GVD) point, and the other core being linear and dispersive. Both 2D and 1D EP systems may be emulated by means of this optical setting. In the framework of this system, we find that, while the uniform state corresponding to the lower branch of the nonlinear dispersion relation is stable against small perturbations, the upper branch is always subject to the modulational instability (MI). The stability and instability are verified by direct simulations too. We analyze collective excitations on top of the stable lower-branch state, which include a Bogoliubov-like gapless mode and a gapped one. Analytical results are obtained for the corresponding sound velocity and energy gap. The effect of a uniform phase gradient (superflow) on the stability is considered too, with a conclusion that the lower-branch state becomes unstable above a critical wavenumber of the flux. Finally, we demonstrate that the stable 1D state may carry robust dark solitons.
11 pages, 9 figures, to appear in Phys. Rev. E
References in corpus (14)
- Quantum fluids of light
- Theory of ultracold Fermi gases
- Direct observation of Anderson localization of matter-waves in a controlled disorder
- Excitations in a non-equilibrium Bose-Einstein condensate of exciton-polaritons
- Quantum-fluid dynamics of microcavity polaritons
- A Bose-Einstein Condensate in a Uniform Light-induced Vector Potential
- Physical realization of -symmetric potential scattering in a planar slab waveguide
- Spontaneous rotating vortex lattices in a pumped decaying condensate
- Collective coherence in planar semiconductor microcavities
- Dynamics and stability of dark solitons in exciton-polariton condensates
- Stochastic classical field model for polariton condensates
- Dark polariton-solitons in semiconductor microcavities
- Semi-discrete composite solitons in arrays of quadratically nonlinear waveguides
- Semi-discrete solitons in arrayed waveguide structures with Kerr nonlinearity