The elements of reality coined by Einstein, Podoslky, and Rosen (EPR) promoted a series of fundamental discussions involving the notion of quantum correlations and physical realism. The superposition principle applied in the double-slit experiment with matter waves highlights the need for a critical review of the adoption of physical realism in the quantum realm. By using a measure of realism, in this work, we use for the first time quantum correlations of noncommuting observables of a single particle to extract information about the behavior of a quantum system. We investigate the role of single particle position-momentum correlations for the degree of irrealism, the interference pattern, wavelike, and particle-like properties in the double-slit setup with matter waves. We find that there is a time of propagation which minimizes position-momentum correlations and this also generates a minimum in the irrealism. Curiously, we show that the maximum number of interference fringes is related with the minimum of the position-momentum correlations and irrealism.
The elements of reality coined by Einstein, Podoslky, and Rosen (EPR) promoted a series of fundamental discussions involving the notion of quantum correlations and physical realism. The superposition principle applied in the double-slit experiment with matter waves highlights the need for a critical review of the adoption of physical realism in the quantum realm. By using a measure of realism, in this work, we use for the first time quantum correlations of noncommuting observables of a single particle to extract information about the behavior of a quantum system. We investigate the role of single particle position-momentum correlations for the degree of irrealism, the interference pattern, wavelike, and particle-like properties in the double-slit setup with matter waves. We find that there is a time of propagation which minimizes position-momentum correlations and this also generates a minimum in the irrealism. Curiously, we show that the maximum number of interference fringes is related with the minimum of the position-momentum correlations and irrealism.
The elements of reality coined by Einstein, Podolsky, and Rosen promoted a series of fundamental discussions involving the notion of quantum correlations and physical realism. The superposition principle applied in the double-slit experiment with matter waves highlights the need for a critical review of the adoption of physical realism in the quantum realm. In this work, we employ a measure of physical irrealism and consider an initial contractive state in the double-slit setup for which position and momentum variables of a single particle are initially correlated. We investigate how the behavior of the irrealism can help us to obtain information about the interference pattern, wavelike, and particlelike properties in the double-slit setup with matter waves. We find that there is a time of propagation that minimizes the irrealism, and around this point the state at the detection screen is squeezed in position and momentum in comparison with the standard Gaussian superposition. Interestingly, we show that the maximum visibility and the number of interference fringes are related to the minimum of the irrealism. Moreover, we demonstrate a monotonic relation between the irrealism and visibility around the time of minimum. Then, we argue how to use these results to indirectly measure the irrealism for position variable from the fringe visibility.
The double-slit experiment has stood for a century as the paradigmatic demonstration of quantum superposition: the standard interpretation holds that a particle passes through both slits simultaneously, existing in a superposition of two spatially separated states. This paper proposes a physically distinct alternative: the particle's matter wave — a real physical wave propagating through space in accordance with de Broglie's relation λ = h/p — passes through both slits, while the particle itself (matter) remains in an undetermined state until a constructive interference maximum is formed at the detection screen. The particle does not simultaneously occupy two locations; the wave does. This distinction eliminates the need for superposition as an ontological commitment while fully reproducing the observed interference pattern. We further show that the disappearance of the interference pattern upon which-path measurement is explained without invoking wavefunction collapse: the measurement interaction redirects the matter wave to a single-slit geometry, eliminating the two-wave interference condition. Three experimentally testable predictions distinguish this framework from the standard interpretation: (1) weak-measurement trajectory reconstruction should reveal single particle paths inconsistent with simultaneous two-slit passage; (2) diffraction fringe spacing should depend on the mass density of the slit material, because denser slit edges generate a steeper refractive-index gradient for the matter wave; (3) the fringe pattern should exhibit a density-dependent phase shift measurable with current matter-wave interferometry technology. This reinterpretation requires no new mathematical formalism — the Schrödinger equation and Born's rule are retained — but replaces the ontological claim of simultaneous multi-location existence with the physically consistent picture of matter-wave propagation through an undetermined-state particle.
We present a treatment of the double-slit interference of matter-waves represented by Gaussian wavepackets. The interference pattern is modelled with Green's function propagator which emphasizes the coordinate correlations and phases. We explore the connection between phases and position–momentum correlations in the intensity, visibility and predictability of the wavepacket interference. This formulation will indicate some aspects that can be useful for theoretical and experimental treatment of particle, atom or molecule interferometry and can be discussed in introductory quantum mechanics courses.
The debate instigated by the seminal works of Einstein, Podolsky, Rosen, and Bell put the notions of realism and nonlocality at the core of almost all philosophical and physical discussions underlying the foundations of quantum mechanics. However, while experimental criteria and quantifiers are by now well established for nonlocality, there is no clear quantitative measure for the degree of reality associated with continuous variables such as position and momentum. This work aims at filling this gap. Considering position and momentum as effectively discrete observables, we implement an operational notion of projective measurement and, from that, a criterion of reality for theses quantities. Then we introduce a quantifier for the degree of irreality of a discretized continuous variable which, when applied to the conjugated pair position-momentum, is shown to obey an uncertainty relation, meaning that quantum mechanics prevents classical realism for conjugated quantities. As an application of our formalism, we study the emergence of elements of reality in an instance where a Gaussian state is submitted to the dissipative dynamics implied by the Caldirola-Kanai Hamiltonian. In particular, at equilibrium, we make some links with the measurement problem and identify aspects that can be taken as the quantum counterpart for the notion of rest.
Paper 74 — No Quantum Superposition This paper argues, by reductio ad absurdum, that the physical realisation of superposition — simultaneous multi-location existence — is incompatible with seven independent and well-established physical principles: (1) the observational fact that no infinite physical quantity has ever been measured; (2) conservation of energy; (3) the mass-energy equivalence E = mc²; (4) the Bekenstein entropy bound; (5) the second law of thermodynamics; (6) the Heisenberg uncertainty principle; and (7) causality. The foundational identification is that information, energy, and mass stand in proportional existential relation (Bekenstein bound: I ∝ M; Landauer principle: ΔE ∝ ΔI; mass-energy equivalence: E = mc²). Complete superposition requires infinite information processing, and therefore infinite energy and infinite mass — quantities universally absent from the observational record of physics. Finite N-state superposition is excluded by a complementary argument: maintaining N states simultaneously requires N times the information-processing load of a single undetermined state, violating the principle that nature selects minimum-load configurations. The positive alternative proposed is the undetermined state: during matter-wave propagation, the matter wave is real and physically present, but matter has not yet appeared at any location. This is not a hidden-variable state but an ontological absence of localisation prior to the formation of a constructive interference maximum. Paper 75 — The Double-Slit Experiment Reinterpreted This paper applies the undetermined-state ontology to the paradigmatic demonstration of quantum mechanics. The de Broglie matter wave — a real physical wave — passes through both slits, while the particle remains in an undetermined state until a constructive interference maximum is formed at the detection screen. The disappearance of the interference pattern upon which-path measurement is explained without wavefunction collapse: the measurement interaction physically disrupts the matter wave's coherent two-slit propagation. Three experimentally testable predictions distinguish this framework: (1) weak-measurement trajectory reconstruction should reveal single-path trajectories inconsistent with simultaneous two-slit passage; (2) diffraction fringe spacing should depend on the mass density of the slit material, because denser slit edges generate a steeper refractive-index gradient; (3) the fringe pattern should exhibit a density-dependent phase shift measurable with current matter-wave interferometry technology. The Schrödinger equation and Born's rule are retained without modification. Paper 76 — Discriminating Experiments for the Constructive-Interference Account of Gravity This paper derives the specific numerical values predicted by Paper 29 — n(r) from the Schwarzschild metric, Δφ = k₀∫[n₁(r)−n₂(r)]dr from the medium-structure integral, and Δx_max = f(∇n, geometry, λ₀) from the interference structure — and assesses whether current experimental technology can measure the gap between Paper 29's predictions and standard QM's predictions. Three formal conditions for a discriminating experiment are established: structural absence of the variable from standard QM, signal exceeding current resolution, and impossibility of alternative explanation. Two experimental classes satisfy all three conditions with existing apparatus: COW path-geometry (predicted δ(Δφ) ~ 10⁻³ rad vs. resolution ~10⁻⁴ rad, path shape structurally absent from the standard COW formula) and slit-material density (predicted Δx_max ~ tens of nm vs. resolution 1–5 nm, material density structurally absent from Δy ≈ λL/a). Cumulative agreement across both systems constitutes genuine inductive support for the proposed mechanism. Paper 77 — From Electrons to Fullerenes This paper addresses three questions that Paper 76 does not: (1) why the slit-material density experiment has never been performed in the hundred years since matter-wave interferometry began — the answer being that standard QM contains no density variable in the slit formula, so experimenters had no reason to vary it, with the Copenhagen prohibition on mechanism questions as the deeper structural reason; (2) why confirmation in exactly two systems — electrons and fullerenes C₆₀ — is sufficient to establish the theoretical outline across six orders of magnitude in mass, because these systems are maximally independent in particle type, mass, apparatus, energy scale, and decoherence environment; (3) what confirmation across this mass range would establish for physics: the first experimentally supported identification of the physical mechanism of gravity, the first experimentally verifiable quantum-gravity connection at accessible energy scales, a physical grounding of Born's rule, and a mechanistic account of the measurement problem. A complete three-layer control protocol for excluding the slit-width confound is specified. Paper 78 — A Three-Dimensional Experimental Matrix This paper extends the experimental programme by introducing slit thickness as a third independent variable alongside matter-wave species and slit-material density. The wave-mechanical account predicts that phase shift scales linearly with slit thickness d: Δφ(ρ,d) = (2π/λ)·[n(ρ)−1]·d — a prediction structurally absent from standard QM, which assigns no physical role to slit thickness. The resulting 5×5×3 matrix of 75 independent measurements has a random coincidence probability of approximately 1/1,728,000, rendering chance agreement with theoretical prediction physically impossible. Three-layer control protocols for fabrication, TEM cross-section verification, and linearity testing are specified for the thickness dimension. Together, the five papers constitute a complete programme: ontological foundation (P74), phenomenological reinterpretation (P75), formal discriminating analysis (P76), strategic and historical argument (P77), and three-dimensional experimental design (P78).
abstract We report the findings of asymmetrical double-slit experiments conducted under Fraunhofer far-field conditions, within the single-photon approximation framework. A notable outcome of these experiments is the consistent observation of interference effects at the first main diffraction minima that surpass the limit set by the complementarity principle D + V = 1. Specifically, we identify anomalous correlations between the D-particle distinguishability and the V-wave visibility, where D + V > 1., suggesting that, within the same experimental context, a significant number of photons exhibit both wave-like and particle-like behavior simultaneously. In the absence of a more comprehensive theoretical account, this anomalous interference may serve as empirical support for the objective physical reality of quantum matter, which stands in contrast to the foundational tenets of the Copenhagen school of quantum mechanics.