Macroscopic realism, wave-particle duality and the superposition principle

Lars‐Göran Johansson

Royan Rosche

Nikolay Leonidovich Chuprikov

On the basis of our model of a one-dimensional (1D) completed scattering (Russian Physics, 49, p.119 and p.314 (2006)) we argue that the linear formalism of quantum mechanics (QM) respects the principles of the macroscopic realism (J. Phys.: Condens. Matter, 14, R415-R451 (2002)). In QM one has to distinguish two kinds of pure ensembles: pure unentangled ensembles to be macroscopically inseparable, and pure entangled ones to be macroscopically separable. A pure entangled ensemble is an intermediate link between a pure unentangled ensemble and classical mixture. Like the former it strictly respects the linear formalism of QM. Like the latter it is decomposable into macroscopically distinct subensembles, in spite of interference between them; our new model exemplifies how to perform such a decomposition in the case of a 1D completed scattering. To respect macroscopic realism, the superposition principle must be reformulated: it must forbid introducing observables for entangled states.

Chen Shu

This paper proposes an alternative interpretation of quantum phenomena, addressing the long-standing division between microscopic and macroscopic physical rules. It argues that apparent differences in quantum behavior stem from temporal sampling granularity, relativistic time dilation, and optical signal superposition, rather than inherent properties of matter. Using classical optical imaging as an analogy and a near-light-speed thought experiment, the study demonstrates that wave-particle duality and superposition are not exclusive to microscopic particles. When observed under extreme conditions, macroscopic objects such as the Earth also exhibit quantum characteristics. The work presents a unified framework linking quantum mechanics, special relativity, and classical optics, offering a new perspective on the fundamental nature of observation.

A. J. Leggett

Mohd Asad Siddiqui, Tabish Qureshi

According to Bohr's principle of complementarity, a quanton can behave either as a wave or a particle, depending on the choice of the experimental setup. Some recent two-path interference experiments have devised methods where one can have a quantum superposition of the two choices, thus indicating that a quanton may be in a superposition of wave and particle natures. These experiments have been of interest from the point of view of Wheeler's delayed-choice experiment. However, it has also been claimed that this experiment can violate complementarity. Here we theoretically analyze a multipath interference experiment that has a which-path detector in a quantum superposition of being present and absent. We show that a tight multipath wave-particle duality relation is respected in all such situations, and complementarity holds well. The apparent violation of complementarity may be due to incorrect evaluation of path distinguishability in such scenarios.