Information processing with topologically protected vortex memories in   exciton-polariton condensates
  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 simple 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. 
H. Sigurdsson, O. A. Egorov, X. Ma, I. A. Shelykh, T. C. H. Liew
cond-mat.quant-gas