Why interference phenomena do not capture the essence of quantum theory

Abstract

Quantum interference phenomena are widely viewed as posing a challenge to the classical worldview. Feynman even went so far as to proclaim that they are the only mystery and the basic peculiarity of quantum mechanics. Many have also argued that such phenomena force us to accept a number of radical interpretational conclusions, including: that a photon is neither a particle nor a wave but rather a schizophrenic sort of entity that toggles between the two possibilities, that reality is observer-dependent, and that systems either do not have properties prior to measurements or else have properties that are subject to nonlocal or backwards-in-time causal influences. In this work, we show that such conclusions are not, in fact, forced on us by the phenomena. We do so by describing an alternative to quantum theory, a statistical theory of a classical discrete field (the 'toy field theory') that reproduces the relevant phenomenology of quantum interference while rejecting these radical interpretational claims. It also reproduces a number of related interference experiments that are thought to support these interpretational claims, such as the Elitzur-Vaidman bomb tester, Wheeler's delayed-choice experiment, and the quantum eraser experiment. The systems in the toy field theory are field modes, each of which possesses, at all times, both a particle-like property (a discrete occupation number) and a wave-like property (a discrete phase). Although these two properties are jointly possessed, the theory stipulates that they cannot be jointly known. The phenomenology that is generally cited in favour of nonlocal or backwards-in-time causal influences ends up being explained in terms of inferences about distant or past systems, and all that is observer-dependent is the observer's knowledge of reality, not reality itself.

Classical analogue of quantum superdense coding and communication advantage of a single quantum

“…It is worth interesting to study whether the quantum advantage observed here has some deeper connection with this no-go result. The quantum advantages studied here also welcome a re-look to the claim made in [96]. The toy-bit model proposed there, originally motivated from [97], seems incapable of showing the advantages reported in the present work.…”

Reply to "Comment on 'Why interference phenomena do not capture the essence of quantum theory' "

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Our article [1] argues that the phenomenology of interference that is traditionally regarded as problematic does not, in fact, capture the essence of quantum theory-contrary to the claims of Feynman and many others. It does so by demonstrating the existence of a physical theory, which we term the "toy field theory", that reproduces this phenomenology but which does not sacrifice the classical worldview.

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“…Hance and Hossenfelder claim that the epistemic restriction used in Ref. [1] is different from the one used in Ref. [3], on the grounds that the one stated in Ref.…”

Comment on "Why interference phenomena do not capture the essence of quantum theory" by Catani et al

“…Catani et al recently claimed to be able to reproduce the phenomenology of the double-slit experiment with a deterministic, local, and classical model that respects measurement independence (is not superdeterministic) [2]. They state that the aim of their argument is to falsify Feynman's claim that the double-slit experiment is "impossible, absolutely impossible, to explain in any classical way" and that it "contains the only mystery" of quantum mechanics [3].…”

“…The which-path measurement is assumed to be non-destructive. A summary of the different experiments can be found in Figure 4 in (the Appendix of) Catani et al's paper [2].…”