Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:0902.2615 · Proceedings of the National Academy of Sciences

Two-slit diffraction with highly charged particles: Niels Bohr's consistency argument that the electromagnetic field must be quantized

Gordon Baym, Tomoki Ozawa

Published Feb 14, 2009• 44 citations
arXivHTMLPDF

Abstract

We analyze Niels Bohr's proposed two-slit interference experiment with highly charged particles which argues that the consistency of elementary quantum mechanics requires that the electromagnetic field must be quantized. In the experiment a particle's path through the slits is determined by measuring the Coulomb field that it produces at large distances; under these conditions the interference pattern must be suppressed. The key is that, as the particle's trajectory is bent in diffraction by the slits, it must radiate and the radiation must carry away phase information. Thus, the radiation field must be a quantized dynamical degree of freedom. However, if one similarly tries to determine the path of a massive particle through an inferometer by measuring the Newtonian gravitational potential the particle produces, the interference pattern would have to be finer than the Planck length and thus indiscernible. Unlike for the electromagnetic field, Bohr's argument does not imply that the gravitational field must be quantized.

DOI
10.1073/pnas.0813239106

Related papers

Interference with electrons: from thought to real experiments

Gioṙgio Matteucci

The two-slit interference experiment is usually adopted to discuss the superposition principle applied to radiation and to show the peculiar wave behaviour of material particles. Diffraction and interference of electrons have been demonstrated using, as interferometry devices, a hole, a slit, double hole, two-slits, an electrostatic biprism etc. A number of books, short movies and lectures on the web try to popularize the mysterious behaviour of electrons on the basis of Feynman thought experiment which consists of a Young two-hole interferometer equipped with a detector to reveal single electrons. A short review is reported regarding, i) the pioneering attempts carried out to demonstrate that interference patterns could be obtained with single electrons through an interferometer and, ii) recent experiments, which can be considered as the realization of the thought electron interference experiments adopted by Einstein-Bohr and subsequently by Feynman to discuss key features of quantum physics.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Nov 18, 2013•5 citations

Should We Interpret Quantum Mechanics According to Bohr

Shubhayan Sarkar

I present here a thought experiment which violates the most widely accepted interpretation of quantum mechanics “The Copenhagen Interpretation” and Bohr’s complementarity which says that there is no meaning of the state of a particle until it is observed and the act of observation might change it. The experiment consists of a double slit apparatus which is modified by putting a second double slit apparatus between the source and the original apparatus with certain conditions imposed on both the apparatuses using the facts of interference and diffraction. A striking paradox emerges if we consider the arguments of Bohr’s complementarity, i.e. the photon travels through both the paths simultaneously in a double slit apparatus whenever there is interference. It turns out that this paradox can be resolved only if the photon travels through one path even if interference fringes are visible.

•Mar 1, 2017•0 citations

One- and two-slit experiments with photons and electrons: A proper resolution

Andrew Das Arulsamy

We construct proper microscopic propositions to consistently explain the interference patterns obtained for electrons and photons in well-defined one- and two-slit experiments. Our propositions are also made explicit on the basis of quantum mechanics with proper quantitative analysis to support the correctness of the physical mechanisms proposed herein, which obey the wave-particle duality. In particular, our propositions and theoretical analysis demonstrate that for single-photon detection (after time integration), we cannot produce interference pattern if the usual diffraction slits are replaced with slit holes such that the non-transparent slit material does not permit photons to transmit, reflect internally or refract. However, the said non-transparent slit material with slit holes can produce the usual interference pattern with electromagnetic waves.

•May 16, 2023•0 citations

How Could Classical Electrons Acquire Double-Slit Quantum Interference via Interacting with Stochastic Quantum Fields

Jau Tang, Chien-Cheng Chang

Quantum interference is traditionally interpreted as evidence of intrinsic wave–particle duality, invoking self-interference and wavefunction superposition. Here, we propose an alternative causal framework in which interference arises from interactions between a classical electron and a quantized electromagnetic field. In this picture, electrons follow definite, localized trajectories and produce discrete detection events, while the observed interference pattern emerges statistically from stochastic, nonlocal momentum transfers mediated by quantized field modes. Numerical simulations of the double-slit experiment show that dot-like interference fringes arise without invoking wavefunction collapse or intrinsic matter waves. Doubling the electron mass narrows the fringe spacing in agreement with de Broglie scaling, indicating that the effective wavelength emerges dynamically from particle–field coupling rather than representing an inherent property of the particle. The formulation is based on a rigorously defined Hamiltonian and derived equations describing electromagnetic coupling between particles and the slit environment. Although neutral particles such as neutrons or atoms carry no net charge monopoles, they possess electric or magnetic dipole and higher multipole moments that enable electromagnetic interactions with the slit apparatus, allowing discrete momentum transfer through the quantized field. Our simulations show that interference fringes arise from intermittent singleparticle detection events caused by stochastic momentum impulses from quantized electromagnetic modes. These results suggest a reinterpretation of wave–particle duality: the apparent wave-like behavior of matter may arise from interaction with the inherently wave-like quantized electromagnetic field—whose quanta are photons, the massless U(1)-gauge bosons—rather than from an intrinsic wave nature of the particles themselves. Our analysis is rigorous and is not speculative, because the proposed Hamiltonian for this system is physical. Within this nonlocal hidden-variable framework, the dot-like interference pattern observed in the double-slit experiment emerges from individual electrons traversing one slit at a time while receiving discrete momentum impulses from stochastic, spatially extended quantized electromagnetic fields.

International Journal of Quantum Technologies•Apr 6, 2026•0 citations

Complementarity in the double-slit experiment: Quantum nonseparability and a quantitative statement of Bohr's principle

William K. Wootters, Wojciech Hubert Zurek

A detailed analysis of Einstein's version of the double-slit experiment, in which one tries to observe both wave and particle properties of light, is performed. Quantum nonseparability appears in the derivation of the interference pattern, which proves to be surprisingly sharp even when the trajectories of the photons have been determined with fairly high accuracy. An information-theoretic approach to this problem leads to a quantitative formulation of Bohr's complementarity principle for the case of the double-slit experiment. A practically realizable version of this experiment, to which the above analysis applies, is proposed.

Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields•Jan 15, 1979•617 citations

Non-Interference Pattern Evolving to Interference Pattern; Non-Diffraction Pattern Evolving to Diffraction Pattern; Two Non-Diffraction Patterns Evolving to Interference-Pattern-Embedded-in-Diffraction Patterns--- Wave-Wave Interference to Photon-Photon Interaction

Hui Peng

We experimentally show novel phenomena: (1) in the same double slit or cross double slit experiment, within macroscopic distances from diaphragm, the patterns are non-interference and gradually evolve to the interference patterns near/on the screen; (2) in the same single slit or cross single slit experiment, within macroscopic distances from diaphragm, the patterns are non-diffraction and gradually evolve to the diffraction patterns near/on the screen; (3) in the same non-parallel-two-slits experiment, within macroscopic distances from diaphragm, the patterns are non-diffraction and gradually evolve to the diffraction-interference-hybrid patterns; (4) the diffraction-interference-hybrid patterns depend on the angle between two slits. Those novel phenomena: (1) challenge the conventional light wave interpretations of the physical optics, the electromagnetic wave and the quantum probability waves, namely, those interpretations are incomplete; (2) challenging Bohr’s complementarity principle and the wave-particle duality; (3) suggest that it is the photon-photon interaction, instead of the wave-wave interference, that produces the phenomena. To interpret consistently above phenomena is the challenge and demands new theory.

International Journal of Physics•Feb 4, 2024•0 citations
We analyze Niels Bohr's proposed two-slit interference experiment with highly charged particles which argues that the consistency of elementary quantum mechanics requires that the electromagnetic field must be quantized. In the experiment a particle's path through the slits is determined by measuring the Coulomb field that it produces at large distances; under these conditions the interference pattern must be suppressed. The key is that, as the particle's trajectory is bent in diffraction by the slits, it must radiate and the radiation must carry away phase information. Thus, the radiation field must be a quantized dynamical degree of freedom. However, if one similarly tries to determine the path of a massive particle through an inferometer by measuring the Newtonian gravitational potential the particle produces, the interference pattern would have to be finer than the Planck length and thus indiscernible. Unlike for the electromagnetic field, Bohr's argument does not imply that the gravitational field must be quantized.
The two-slit interference experiment is usually adopted to discuss the superposition principle applied to radiation and to show the peculiar wave behaviour of material particles. Diffraction and interference of electrons have been demonstrated using, as interferometry devices, a hole, a slit, double hole, two-slits, an electrostatic biprism etc. A number of books, short movies and lectures on the web try to popularize the mysterious behaviour of electrons on the basis of Feynman thought experiment which consists of a Young two-hole interferometer equipped with a detector to reveal single electrons. A short review is reported regarding, i) the pioneering attempts carried out to demonstrate that interference patterns could be obtained with single electrons through an interferometer and, ii) recent experiments, which can be considered as the realization of the thought electron interference experiments adopted by Einstein-Bohr and subsequently by Feynman to discuss key features of quantum physics.
I present here a thought experiment which violates the most widely accepted interpretation of quantum mechanics “The Copenhagen Interpretation” and Bohr’s complementarity which says that there is no meaning of the state of a particle until it is observed and the act of observation might change it. The experiment consists of a double slit apparatus which is modified by putting a second double slit apparatus between the source and the original apparatus with certain conditions imposed on both the apparatuses using the facts of interference and diffraction. A striking paradox emerges if we consider the arguments of Bohr’s complementarity, i.e. the photon travels through both the paths simultaneously in a double slit apparatus whenever there is interference. It turns out that this paradox can be resolved only if the photon travels through one path even if interference fringes are visible.
We construct proper microscopic propositions to consistently explain the interference patterns obtained for electrons and photons in well-defined one- and two-slit experiments. Our propositions are also made explicit on the basis of quantum mechanics with proper quantitative analysis to support the correctness of the physical mechanisms proposed herein, which obey the wave-particle duality. In particular, our propositions and theoretical analysis demonstrate that for single-photon detection (after time integration), we cannot produce interference pattern if the usual diffraction slits are replaced with slit holes such that the non-transparent slit material does not permit photons to transmit, reflect internally or refract. However, the said non-transparent slit material with slit holes can produce the usual interference pattern with electromagnetic waves.
Quantum interference is traditionally interpreted as evidence of intrinsic wave–particle duality, invoking self-interference and wavefunction superposition. Here, we propose an alternative causal framework in which interference arises from interactions between a classical electron and a quantized electromagnetic field. In this picture, electrons follow definite, localized trajectories and produce discrete detection events, while the observed interference pattern emerges statistically from stochastic, nonlocal momentum transfers mediated by quantized field modes. Numerical simulations of the double-slit experiment show that dot-like interference fringes arise without invoking wavefunction collapse or intrinsic matter waves. Doubling the electron mass narrows the fringe spacing in agreement with de Broglie scaling, indicating that the effective wavelength emerges dynamically from particle–field coupling rather than representing an inherent property of the particle. The formulation is based on a rigorously defined Hamiltonian and derived equations describing electromagnetic coupling between particles and the slit environment. Although neutral particles such as neutrons or atoms carry no net charge monopoles, they possess electric or magnetic dipole and higher multipole moments that enable electromagnetic interactions with the slit apparatus, allowing discrete momentum transfer through the quantized field. Our simulations show that interference fringes arise from intermittent singleparticle detection events caused by stochastic momentum impulses from quantized electromagnetic modes. These results suggest a reinterpretation of wave–particle duality: the apparent wave-like behavior of matter may arise from interaction with the inherently wave-like quantized electromagnetic field—whose quanta are photons, the massless U(1)-gauge bosons—rather than from an intrinsic wave nature of the particles themselves. Our analysis is rigorous and is not speculative, because the proposed Hamiltonian for this system is physical. Within this nonlocal hidden-variable framework, the dot-like interference pattern observed in the double-slit experiment emerges from individual electrons traversing one slit at a time while receiving discrete momentum impulses from stochastic, spatially extended quantized electromagnetic fields.
A detailed analysis of Einstein's version of the double-slit experiment, in which one tries to observe both wave and particle properties of light, is performed. Quantum nonseparability appears in the derivation of the interference pattern, which proves to be surprisingly sharp even when the trajectories of the photons have been determined with fairly high accuracy. An information-theoretic approach to this problem leads to a quantitative formulation of Bohr's complementarity principle for the case of the double-slit experiment. A practically realizable version of this experiment, to which the above analysis applies, is proposed.
We experimentally show novel phenomena: (1) in the same double slit or cross double slit experiment, within macroscopic distances from diaphragm, the patterns are non-interference and gradually evolve to the interference patterns near/on the screen; (2) in the same single slit or cross single slit experiment, within macroscopic distances from diaphragm, the patterns are non-diffraction and gradually evolve to the diffraction patterns near/on the screen; (3) in the same non-parallel-two-slits experiment, within macroscopic distances from diaphragm, the patterns are non-diffraction and gradually evolve to the diffraction-interference-hybrid patterns; (4) the diffraction-interference-hybrid patterns depend on the angle between two slits. Those novel phenomena: (1) challenge the conventional light wave interpretations of the physical optics, the electromagnetic wave and the quantum probability waves, namely, those interpretations are incomplete; (2) challenging Bohr’s complementarity principle and the wave-particle duality; (3) suggest that it is the photon-photon interaction, instead of the wave-wave interference, that produces the phenomena. To interpret consistently above phenomena is the challenge and demands new theory.