Multiphoton Non-Local Quantum Interference Controlled by an Undetected Photon

This article develops an expanded critical–propositional analysis of Kaiyi Qian et al.’s 2023 experiment, “Multiphoton Non-local Quantum Interference Controlled by an Undetected Photon,” published in Nature Communications 14, article 1480, DOI https://doi.org/10.1038/s41467-023-37228-y, in systematic dialogue with the Theory of Objectivity (TO) formulated by Vidamor Cabannas and Denivaldo Silva. Qian et al. experimentally realized multiphoton frustrated quantum interference by exploiting the coherent superposition of alternative physical origins of a four-photon product state. Their experiment is especially significant because the phase of a photon that is not detected can control measurable interference patterns involving the remaining detected photons. The reported four-fold interference visibility was V4 = (75.47 ± 2.99)%, three-fold coincidence interference controlled by the undetected photon exhibited a visibility of V3 = (29.84 ± 1.05)%, and even two-fold coincidences displayed phase-dependent interference with a visibility of V2 = (11.42 ± 0.38)%. These results constitute an experimentally controlled demonstration that direct detection of every participating quantum degree of freedom is not required for that degree of freedom to remain physically relevant to the global interference process (Qian et al., 2023). The present analysis examines whether and to what extent these results can be placed in constructive dialogue with the seven Absolute Truths proposed by TO, while carefully distinguishing empirical confirmation, structural compatibility, heuristic analogy, indirect corroboration, and theory-specific corroboration. Particular attention is given to the Fourth Absolute Truth concerning boundaries, the Fifth Absolute Truth concerning relational observation, and the Seventh Absolute Truth concerning a transcendent element identified in later TO formulations with knowledge or information produced in atomic relations and regarded as equivalent to atomic radiation. Qian et al.’s experiment is especially relevant to the Fifth Absolute Truth because the experimentally consequential role of an undetected photon demonstrates that physical participation does not depend on human observation or on the direct registration of every constituent of the relevant quantum process. This point is compatible with TO’s explicit distinction between human observation and ontological relational observation. The article argues that the experiment offers meaningful indirect empirical sup- port for several operational bridges proposed by TO—especially its non-anthropocentric conception of observation, its emphasis on relational determination, and its attribution of physical significance to information-bearing relations. Nevertheless, the experiment does not establish the full modal claims of TO. In particular, Qian et al. do not test the TO requirement that logical existence involves at least two other elements, do not detect the unique individual magnetic field postulated by the Second Absolute Truth, and do not establish that information constitutes a transcendent substance ontologically equivalent to atomic radiation. Nor does the experiment test the TO cosmogonic theorem or its cosmological eras. The analysis therefore proposes a disciplined distinction between compatibility and confirmation. The Qian experiment can be treated as an unusually fertile empirical domain for operationalizing TO, but a stronger scientific claim would require TO to derive quantitative predictions from its axioms, reproduce or constrain the experimen- tally observed phase dependences and visibility bounds, and ideally predict effects that differ from standard quantum theory. The article concludes by proposing a research program based on controlled distinguishability, undetected-photon phase manipulation, boundary transformations, multi-element relational configurations, and searches for theory-specific deviations.