A system is said to be entangled if its state cannot be expressed as a product of states. (i.e $\psi_{AB}\neq\psi_A \psi_B$) Physically it is a direct result of conservation of energy/momentum, but what (quantum) mechanical procedure(s) take a particle or particles and create an entangled state, and how would this procedure confirm that a force is quantum in nature?
This question comes from an experiment designed to test whether gravity is in fact a quantum force; see https://www.quantamagazine.org/physicists-find-a-way-to-see-the-grin-of-quantum-gravity-20180306/. The article makes me think that the particle(s) to be entangled interact through some fundamental force, and if this force is quantum then the interaction may cause a superposition of states that may be entangled, otherwise the interaction will be deterministic and no superposition may occur; however, I could not find some analysis of that statement and it thus seems non sequitur.
UPDATE:
Thanks to all that have answered. Each answer (so far) has given me a more clear understanding of how states are entangled; however, they are missing the second part to the question, perhaps because I was not clear enough:
From the answers I see that an entangled state is created via some operation/evolution (such as CNOT) but if the force in question (i.e. gravity) is not quantum in nature does it imply that such an operation does not exist, and if not, may a mathematical proof be provided?
No comments:
Post a Comment