Entanglementthat

Entanglementthat is a term used in speculative discussions about quantum correlations to denote a hypothetical form of entanglement that incorporates a contextual qualifier, often described as a relational tag attached to the joint state. In this idea, two or more subsystems exhibit correlations that cannot be fully characterized by standard entanglement alone without accounting for an external context parameter.

Origins and usage: The term is not part of established quantum information theory. It emerged mainly in online forums and thought experiments in the early 2020s as a playful extension of the concept of entanglement, intended to explore how context and relational properties might affect observed correlations.

Conceptual framing: In a speculative model, the joint state is written with an additional context variable T, such as a hypothetical ρ_A,B|T. The entanglementthat resource would be nonzero only for certain ranges of T, illustrating a conditional or context-dependent type of correlation that could resemble entanglement when conditioned on T. Proponents use this framing to discuss how external factors or relational properties might influence quantum correlations beyond traditional entanglement measures.

Reception and assessment: Most physicists treat entanglementthat as a thought experiment rather than a physical resource. Critics argue that adding a context variable risks conflating contextuality with entanglement and may not yield independent operational advantages beyond established resources.

See also: quantum entanglement, contextuality, relational quantum mechanics, decoherence.