Above: Example of a qubit state trajectory in the Bloch ball when interacting with another qubit.

Below: Velocity magnitude profile (bright yellow is the speed of sound) of a weakly interacting Bose gas when its two lowest modes are prepared in a Schrodinger cat state consisting of a superposition of uniformly distributed atoms ("DEAD") and a quantum vortex of unit circulation ("ALIVE"). Distance unit is ξ0 , the vortex core radius.