Fig. 4: Experimental results (generalized skyrmion adders).
From: Perturbation-resilient integer arithmetic using optical skyrmions
a, (Left) The different regions of the Poincaré sphere on which the function of our adder is stable. The top region corresponds to addition; the bottom, to subtraction; and the middle, to both addition and subtraction simultaneously. (Right) A subset of the measured output Stokes fields and computed generalized skyrmion numbers is shown for different levels of disorder (increasing from left to right) and different incident SoPs selected to demonstrate addition, subtraction and simultaneous addition and subtraction. A stereographic projection of the boundary curve is also shown, with the change in skyrmion number of each region labelled. The colour of these labels indicate the generalized skyrmion number corresponding to that region. A complete dataset including details of the incident SoPs and measured Mueller matrices is presented in Supplementary Fig. 4. Technical details such as the formation of small loops due to disorder are also discussed. Last, details of the implementation and experimental assembly are provided in Supplementary Note 1 and Supplementary Fig. 1, respectively. b, Skyrmion number and generalized skyrmion numbers at each level of disorder for different incident SoPs. Note that the generalized skyrmion number is topologically stable even though the usual skyrmion number is not.
