Variational quantum classifiers through the lens of the Hessian
Fig 3
Loss landscape of the parity problem for (θ3 and θ7).
In fig (a, c), the loss landscape is visualized with a local loss function for two parameters θ3 and θ7, where rest of the parameters are set to the optimal values. Moreover, it cannot be visualize for more than 2 parameters for the 3D Loss, because it cannot obtain the full range of loss between (0 and 1). In fig (b, d), the points in contour plots show the direction of improvement in the optimization process i.e. how the parameters are optimized during iterations. Fig (b) is just the zoom-in version of Fig (d) for better clarification. The green color point depicted the optimal value of θ3 and θ7.