

A spin qubit flipping states also flips the field acting on nearby nuclear spins between
two orientations (shown as arrows). The nuclear spin vector follows a path conditional on the specific
trajectory of the qubit, so that they are entangled. 


Examples of magnetic molecules. Top: Fe8. Eight s=5/2 FeIII ions are forming a
total spin S=10 (six spins are parallel and antiparallel to the other two); middle: Ni12 with
a total spin S=12; bottom: Mn12 with a total spin S=10.

