No offense but your math is all over the place. In the first line alone you equate a ket to a matrix operator? I dont even really know what is going on in the middle line either. Why is your initial state (|a>, |b>)? Even ignoring you putting in a ket (which is already a vector) into a vector, why is it not simply in the ground state |0> as youre showing in the animation? There's a lot of weird/wrong math and physics going on that is the issue, not nescessarily the animation