We show theoretically that an open-dissipative polariton condensate confined within a trapping potential and driven by an incoherent pumping scheme gives rise to bistability between odd and even modes of the potential. Switching from one state to the
other can be controlled via incoherent pulsing which becomes an important step towards construction of low-powered opto-electronic devices. The origin of the effect comes from modulational instability between odd and even states of the trapping potential governed by the nonlinear polariton-polariton interactions.
We show that in a non-equilibrium system of an exciton-polariton condensate, where polaritons are generated from incoherent pumping, a ring-shaped pump allows for stationary vortex memory elements of topological charge $m = 1$ or $m = -1$. Using simp
le potential guides we can choose whether to copy the same charge or invert it onto another spatially separate ring pump. Such manipulation of binary information opens the possibility of a new type processing using vortices as topologically protected memory components.
We study theoretically the ground states of topological defects in a spinor four-component condensate of cold indirect excitons. We analyze possible ground state solutions for different configurations of vortices and half-vortices. We show that if on
ly Rashba or Dreselhaus spin-orbit interaction (SOI) for electrons is present the stable states of topological defects can represent a cylindrically symmetric half-vortex or half vortex-antivortex pairs, or a non-trivial pattern with warped vortices. In the presence of both of Rashba and Dresselhaus SOI the ground state of a condensate represents a stripe phase and vortex type solutions become unstable.
