Local disentanglement in relativistic quantum field theory

• Local disentanglement is a necessary condition for the independence of quantum systems.
• We distinguish between absolutely local operations and relatively local operations.
• Local disentanglement in quantum field theory can be achieved by relatively local operations.

This paper discusses a claim by Clifton and Halvorson (2001) that, contrary to non-relativistic quantum mechanics, local operations can never destroy entanglement in relativistic quantum field theory. The impossibility of achieving local disentanglement would raise a threat for the mutual independence between microscopic subsystems. Here, we observe that Clifton and Halvorson no-go result rests on an unnecessarily strong notion of local operations, which we label absolutely local operations, and we argue that a weaker notion, namely that of relatively local operations, is sufficient to guarantee that acting on one subsystem does not have non-local effects on another spacelike separated subsystem. We then show that one can achieve local disentanglement in relativistic quantum field theory by means of relatively local operations. In fact, we prove that, under the split property, there exists a class of disentangling relatively local operations.