Explicit identification of embezzlement unitaries in quantum field theories

Identify and construct explicitly the unitary operators required to perform embezzlement of entanglement in quantum field theories—at least in paradigmatic models such as free quantum field theories—and establish how these unitaries relate to the operational framework of local operations in algebraic quantum field theory.

Background

Building on the result that local algebras in QFT are universal embezzlers, the authors point out the need to move from existence proofs to concrete realizations. Explicit constructions in specific models (e.g., free fields) would bridge the gap between theory and potential applications and clarify their compatibility with operational notions of locality in AQFT.

This problem aims to determine the precise form of the unitaries that achieve embezzlement—e.g., their localization, energy properties, and implementability—and to connect them to the broader discussion about admissible local operations in QFT.