Everything is entangled in quantum mechanics: on the measures of quantum entanglement

Even though quantum entanglement is today’s most essential concept within the new technological era of quantum information processing, we do not only lack a consistent definition of this kernel notion, we are also far from understanding its physical meaning [1]. These failures have led to many problems when attempting to provide a consistent measure or quantification of entanglement. In fact, the two main lines of contemporary research within the orthodox literature have created mazes where inconsistencies and problems are found everywhere. While the operational-instrumentalist approach has failed to explain how inequalities are able to distinguish the classical from the quantum, the geometrical approach has failed to provide a consistent meaningful account of their entropic measure. Taking distance from orthodoxy, in this work, we address the quantification and measure of quantum entanglement by considering a recently presented objective-invariant definition in terms of the coding of intensive relations [2] which allows to escape the widespread relativist account of bases and factorizations [3, 4]. Going beyond the orthodox dualistic reference to “quantum particles” and “clicks” in detectors, we will argue that this new line of research is capable not only to evade the many open problems which appear within the mainstream literature, but is also able to present a consistent and coherent physical understanding of entanglement. The main conclusion of this work is that in quantum mechanics—contrary to what is generally presupposed—all operational expressions found within the laboratory are intrinsically entangled.