When this phenomenon occurs between a region and its compliment, entropy has a leading term proportional to the area of the boundary and subleading terms which depend on the shape of the boundary.
When this phenomenon occurs between a region and its compliment, entropy has a leading term proportional to the area of the boundary and subleading terms which depend on the shape of the boundary. Anton Zeilinger is best known for experiments on particles which experience this phenomenon. It's not mixing, but when a Hamiltonian may be split into the direct product of two factors, the entropy due to this phenomenon is equal to the (*) negative partial trace of the reduced density matrix times the log of that matrix. This phenomenon is absent if the density matrix can be factorized, which is the case for product states. Bell states experience the maximal amount of this phenomenon. Particles in this state were discussed in a paper by Einstein, Podolsky, and Rosen. For 10 points, name this phenomenon which Einstein described as "spooky action at a distance."
When this phenomenon occurs between a region and its compliment, entropy has a leading term proportional to the area of the boundary and subleading terms which depend on the shape of the boundary.
quantum entanglement 