Whether the phenomenon called quantum entanglement it is necessary to describe the physical world or some post-quantum theory without entanglement? In the new study, which says phys.org physics mathematically proved that any theory with a classical limit – when she can describe our observations of the classical world, referring to the classical theory under certain conditions – have to include confusion. Therefore, despite the fact that the confusion is at odds with the classical understanding, it should be inevitable and the most important property of not only quantum theory, but any non-classical theory, has not even been developed.

Physics in the person of Jonathan Richens from Imperial College London and University College London, John Selby from Imperial College London and Oxford University and Sabri al-Safi from the University of Nottingham, has published an article that said that confusion is an inevitable feature of any non-classical theory, Physical Review Letters.

“Quantum theory of many strange features compared with the classical theory” says it richens. “Traditionally, we study how the classical world emerges from quantum, but then we decided to reverse this argument to see how the classical world generates quantum. So we have shown that one of the strangest features of the last quantum entanglement is the inevitable consequence of going beyond the classical theory, or perhaps even a consequence of our inability to relinquish the classical theory, to leave it behind.”

Although the full proof is much more, the basic idea is that any theory that describes reality should behave as a classical theory in a certain limit. This requirement seems rather obvious, but according to physics, it imposes severe restrictions on the structure of any non-classical theory.

Quantum theory satisfies this requirement of the classical limit of the decoherence process. When a quantum system interacts with the external environment, it loses its quantum coherence, connectedness, and everything that makes it quantum. Thus, the system becomes classical and behaves as expected in the classical theory.

Physicists have shown that any non-classical theory that recovers the classical theory must contain entangled States. To prove it, they went the opposite way: for example, such a theory has no confusion. And then they showed that without the involvement of any theory that recovers the classical theory, must itself be a classic – and this contradicts the initial hypothesis that such a theory must be non-classical. This result means that the assumption of lack of involvement in such a theory is false, and hence, any theory of this type needs to have it.

This result can only be the beginning of many other related discoveries, because it opens the possibility that other physical features of quantum theory can be reproduced, simply by demanding from the theory of the existence of the classical limit. Physics suggest that such features as informational causality (a causal link), the bit symmetry and macroscopic locality can be proved, because of this the only requirement. These results also give a more clear idea of what to look for in any future non-classical, petkanova theory.

“My future goals are to see whether the nonlocality of the bell also learned of the existence of the classical limit”, it richens says. “It would be interesting if all of the theory, replacing the classical theory, would violate local realism”.

Local realism is the combination of the principle of locality with the “realistic” assumption that all objects possess “objectively existing” values of their parameters and characteristics for any possible measurement that could be performed on these objects, before these measurements are made. Einstein, being, apparently, a supporter of local realism, liked in this connection to say that the Moon disappears from the sky, even if nobody is watching. These modern quantum mechanics, based on experiments, questioning the adequacy of the model of local realism “device” reality.

Quantum entanglement may be an essential property of reality

Ilya Hel

official channels