So the superposition refers to the two types of spin and after a collision you can infer the spin of the collided particles in the properties of the D2 molecules?
More or less, yeah, because you can measure the molecules' spin and figure the spin of the previous state using conservation of total angular momentum (which is equal to spin + orbital angular momentum, if you know the latter, you can figure out the former...).
This is already the third article today where they discovered the holy grail