The wave-particle duality is the main point of demarcation between quantum and classical physics, and is the quintessential mystery of quantum mechanics. Young's two-slit interference experiment is the arch prototype of actual and gedanken experiments used as a testing ground of this duality. Quantum mechanics predicts that any detector capable of determining the path taken by a particle through one or the other of a two-slit plate will destroy the interference pattern. We will examine both the experimental and theoretical attempts to test this assertion, including a new kind of experiment, and to grasp the underlying truth behind this mystery from the earliest days to the present. Where positions differ, the views of both sides are presented in a balanced approach.
The wave-particle duality is the main point of demarcation between quantum and classical physics, and is the quintessential mystery of quantum mechanics. Young's two-slit interference experiment is the arch prototype of actual and gedanken experiments used as a testing ground of this duality. Quantum mechanics predicts that any detector capable of determining the path taken by a particle through one or the other of a two-slit plate will destroy the interference pattern. We will examine both the experimental and theoretical attempts to test this assertion, including a new kind of experiment, and to grasp the underlying truth behind this mystery from the earliest days to the present. Where positions differ, the views of both sides are presented in a balanced approach.
Abstract The double-slit experiment is a classic experiment that presents the clearest manifestation of wave-particle duality, one of the fundamental principles of quantum mechanics. The double-slit experiment still remains the phenomenon that demonstrates wave-particle duality at the most fundamental level. This phenomenon quantitatively and conceptually demonstrates that microscopic objects can behave like both waves and particles at the same time. This article provides an in-depth analysis of the physical nature of dualism, the mechanism of formation of the interference pattern, and the impact of the act of observation on the dynamics of quantum systems. The need for a new perspective on this topic is due to the fact that the current uncertainty in the interpretation of quantum reality has not yet been completely eliminated, and the boundaries between classical and quantum behavior in microscopic objects are still being explored. The results presented here restructure the deep mechanisms of the interference picture, more clearly frame the relationship between observation and wavefunction collapse, and provide a quantum. Since the article attempts to provide a complete answer to the mechanism of the formation of wave-particle duality, extensive space is given to sections such as historical development, theoretical models, modern research, etc. New approaches to this phenomenon have been developed using modern research and string theory. As a result, a new mathematical expression has been proposed that explains the reasons for the initial emergence of wave-particle duality, and is also important for string theory. The article explains the measurement problem with a more effective physical structure and ontological model.
We report observations of Cross-Double-Slit Experiment and Which-Path-Cross-Double-Slit experiment. Cross-Double-Slit apparatus contains two double-slit, where first double-slit is perpendicular to second double-slit. The first double-slit and the second double-slit generate not only their own interference pattern perpendicular to each other, but also generate “Cross-interference-patterns”. When we do which-way experiment with one of two double-slit, say first double-slit, then its interference pattern disappeared, i.e., photons behave as particles; but the second double-slit’s interference pattern and the cross-interference-pattern still exist; which implies an significant phenomenon that in the same experiment, photons behave as both wave and particle, which is first time caught on film. Thus we suggest to re-study wave-particle duality, which is the basic mystery of quantum mechanics. We postulate that the particle nature of photons is intrinsic; while the wave-like of photons is manifest-behavior.
Young's double slit experiments representing the mystery of quantum mechanics have been descripted by wave theories. To study the mystery, the double slit experiments were extended to the cross-double slit experiments. A description should explain all the double slit and cross-double slit experiments consistently. To test the wave description, the two postulates are proposed, which state that before passing through the double slit and before landing on the detector, photons behave as particles, but not as waves. To test the two postulates, the comprehensive double slit/cross-double slit experiments are proposed and performed. By placing shields and/or blockers near the detector/screen, the comprehensive double slit/cross-double slit experiments show that the fringes are created independently and partially, which discloses the particle nature of photons in the double slit/crossdouble slit experiments and violates the wave descriptions. The comprehensive double slit/cross-double slit experiments provide the comprehensive phenomena for developing theoretical model to study the mystery of double slit, complementarity principle, wave-particle duality, and wave theory of light.
The wave-particle duality mystery, present in the language of quantum physics since its historical origins 100 years ago, has no real correspondence with the actual behaviour of nature when it is observed. The dilemma of the so-called “single particle interference” experiments is not between particles versus waves: the interference in quantum physics is between probability amplitudes for different untagged alternatives in a definite transition between states. This article shows that the same conceptual basis is involved in a plethora of “two-state systems” as a consequence of the linear superposition principle, no matter whether the observables refer to either spatial or internal properties. Several examples, from the Young double-slit interference experiments to neutrino flavour oscillation experiments, are discussed in a common interpretation language.
Particle and wave like properties of photons can impressively be demonstrated in Young’s double slit experiment. Usually, measurements behind the slit provide information either about the path of the single photons or interference can be observed. Today the question of “which-slit” versus “interference” in the double-slit configuration is as relevant as it was in the early days of quantum mechanics. To gain deeper insight we set up an experiment using a pair of photons generated by SPDC pumped with a higher order mode (TEM 01 ). One of the SPDC photons, the signal photon, was used to illuminate the double slit and measure the single photon interference behind it. The other photon, the idler photon, was used in a reference measurement at the position of the slit using a polarizing beam splitter. First, the signal photons were obtained at the position of the slit as a function of the position of the entangled idler photons in a coincidence measurement. From this coincidence measurement the “which-slit” information is available. In a second coincidence measurement the far field interference fringes were obtained for signal photons passing through one of the slits, only, selected by the position of the reference detector measuring the entangled idler photons. The newest results will be presented and discussed. This may provide new insights in the wave-particle dualism and thus inspire the discussion about the nature of photons.
Young’s double slit experiments revived the wave theory of light. The standard interpretation is that the light behaves as waves before and after passing through the double slit, and the superposition of waves produces the interference pattern. Feynman called the double slit experiment the only mystery in quantum mechanics. In this article, we experimentally show the novel universal phenomena: (1) within macro-distance from the diaphragm, the light rays behave as photons and produce non-interference patterns; while near the screen, the photons produce interference patterns; (2) The non-interference patterns evolve to the interference patterns gradually in the same classical wave experiment; (3) the light is photons before and after passing through the double slit; (4) The convex lens stops the further evolution. The experiments: (1) challenge the wave theories of the light; (2) violate both Bohr’s complementarity principle and wave particle duality; (3) provide profound phenomena for developing optics and for studying the nature of light; (4) suggest that a complete theory should be able to consistently interpret all phenomena, including the non-interference pattern, the interference pattern, and the evolution from the non-interference to the interference pattern in the wave experiment; (5) show a new mystery that photons, as particles, distribute as waves.