Double-slit Research Articles

Double-Slit Interference in the Ion Dynamics of Dissociative Photoionization.

The ion momentum distribution in the x-ray-induced dissociative photoionization of molecules is investigated, treating the ionization analytically under the Born-Oppenheimer approximation and simulating numerically the ion motion via the Schrödinger equation. The ion-photoelectron entanglement transfers information of the electronic interference to the ion dynamics. As a consequence, the ion momentum distributions of dissociative molecular photoionization present Young's double-slit interference when the photoelectron emission angle is fixed. We demonstrate that double-slit interference signatures persist in the ion longitudinal momentum shift even when the information of the correlated photoelectron is lost, which is the case for heteronuclear molecules when an additional photoelectron recoil momentum arises due to the different ion masses. For the case of sequential double ionization, we show that double-slit interference in the ion dynamics can be utilized for coherent control of the molecular dynamics.

Revisiting wave–particle duality in Bohr–Einstein debate

The notion of wave–particle duality remains one of the most debated subjects in the history of quantum physics. The most famous debate on the subject occurred between Bohr and Einstein. In this work, we revisit the wave–particle duality in the Bohr–Einstein debate from the viewpoint of the recently established duality-entanglement relation. We show that the duality-entanglement relation can provide a valuable framework for quantitative analysis of the Einstein's gedanken double-slit experiment and clarify some of its fundamental aspects.

Two-photon excitation with finite pulses unlocks pure dephasing-induced degradation of entangled photons emitted by quantum dots

Semiconductor quantum dots have emerged as an especially promising platform for the generation of polarization-entangled photon pairs. However, it was demonstrated recently that the two-photon excitation scheme employed in state-of-the-art experiments limits the achievable degree of entanglement by introducing which-path information. In this work, the combined impact of two-photon excitation and longitudinal acoustic phonons on photon pairs emitted by strongly-confining quantum dots is investigated. It is found that phonons further reduce the achievable degree of entanglement even in the limit of vanishing temperature due to phonon-induced pure dephasing and phonon-assisted one-photon processes, which increase the reexcitation probability. In addition, the degree of entanglement, as measured by the concurrence, decreases with rising temperature and/or pulse duration, even if the excitonic fine-structure splitting is absent and when higher electronic states are out of reach. Furthermore, in the case of finite fine-structure splittings, phonons enlarge the discrepancy in concurrence for different laser polarizations.

Double-slit X-ray dynamical diffraction in curved crystals.

The theoretical investigation of double-slit X-ray dynamical diffraction in curved crystals shows that Young's interference fringes are formed. An expression for the period of the fringes has been established which is polarization sensitive. The position of the fringes in the cross section of the beam depends on the deviation from the Bragg exact orientation for a perfect crystal, on the curvature radius and on the thickness of the crystal. This type of diffraction can be used for determination of the curvature radius by measuring the shift of the fringes from the centre of the beam.

Neutron Interferometer Experiments Studying Fundamental Features of Quantum Mechanics

Quantum theory provides us with the best account of microscopic components of matter as well as of radiation. It was introduced in the twentieth century and has experienced a wide range of success. Although the theory’s probabilistic predictions of final experimental outcomes is found to be correct with high precision, there is no general consensus regarding what is actually going on with a quantum system “en route”, or rather the perceivable intermediate behavior of a quantum system, e.g., the particle’s behavior in the double-slit experiment. Neutron interferometry using single silicon perfect crystals is established as a versatile tool to test fundamental phenomena in quantum mechanics, where an incident neutron beam is coherently split in two or three beam paths with macroscopic separation of several centimeters. Here, we present quantum optical experiments with these matter-wave interferometers, studying the effect of the quantum Cheshire Cat in some variants, the neutron’s presence in the paths of the interferometer as well as the direct test of a commutation relation. To reduce disturbances induced by the measurement, the interaction strength is lessened and so-called weak interactions are exploited by employing pre- and post-selection procedures. All results of the experiments confirm the predictions of quantum theory; the observed behaviors of the neutron between the pre- and post-selection in space and time emphasize striking and counter-intuitive aspects of quantum theory.

Maxwell-Dirac Isomorphism Revisited: From Foundations of Quantum Mechanics to Geometrodynamics and Cosmology

Although electrons (fermions)and photons (bosons) produce the same interference patterns in the two-slit experiments, known in optics for photons since the 17th Century, the description of these patterns for electrons and photons thus far was markedly different. Photons are spin one, relativistic and massless particles while electrons are spin half massive particles producing the same interference patterns irrespective to their speed. Experiments with other massive particles demonstrate the same kind of interference patterns. In spite of these differences, in the early 1930s of the 20th Century, the isomorphism between the source-free Maxwell and Dirac equations was established. In this work, we were permitted replace the Born probabilistic interpretation of quantum mechanics with the optical. In 1925, Rainich combined source-free Maxwell equations with Einstein’s equations for gravity. His results were rediscovered in the late 1950s by Misner and Wheeler, who introduced the word "geometrodynamics” as a description of the unified field theory of gravity and electromagnetism. An absence of sources remained a problem in this unified theory until Ranada’s work of the late 1980s. However, his results required the existence of null electromagnetic fields. These were absent in Rainich–Misner–Wheeler’s geometrodynamics. They were added to it in the 1960s by Geroch. Ranada’s solutions of source-free Maxwell’s equations came out as knots and links. In this work, we establish that, due to their topology, these knots/links acquire masses and charges. They live on the Dupin cyclides—the invariants of Lie sphere geometry. Symmetries of Minkowski space-time also belong to this geometry. Using these symmetries, Varlamov recently demonstrated group-theoretically that the experimentally known mass spectrum for all mesons and baryons is obtainable with one formula, containing electron mass as an input. In this work, using some facts from polymer physics and differential geometry, a new proof of the knotty nature of the electron is established. The obtained result perfectly blends with the description of a rotating and charged black hole.

Delayed-Choice Quantum Erasers and the Einstein-Podolsky-Rosen Paradox

Considering the delayed-choice quantum eraser using a Mach-Zehnder interferometer with a nonsymmetric beam splitter, we explicitly demonstrate that it shares exactly the same formal structure with the Einstein-Podolsky-Rosen-Bohm (EPR-Bohm) experiment. Therefore, the effect of quantum erasure can be understood in terms of the standard EPR correlation. Nevertheless, the quantum eraser still raises a conceptual issue beyond the standard EPR paradox, if counterfactual reasoning is taken into account. Furthermore, the quantum eraser experiments can be classified into two major categories: the entanglement quantum eraser and the Scully-Dr\"uhl-type quantum eraser. These two types are formally equivalent to each other, but conceptually the latter presents a "mystery" more prominent than the former. In the Scully-Dr\"uhl-type quantum eraser, the statement that the which-way information can be influenced by the delayed-choice measurement is not purely a consequence of counterfactual reasoning but bears some factual significance. Accordingly, it makes good sense to say that the "record" of the which-way information is "erased" if the potentiality to yield a conclusive outcome that discriminates the record is eliminated by the delayed-choice measurement. We also reconsider the quantum eraser in the many-worlds interpretation (MWI), making clear the conceptual merits and demerits of the MWI.

Double-slit interference experimental platform based on a Sagnac interferometer.

In this paper, we build a Young's double-slit experimental platform with adjustable multiparameters by inserting a single slit in a Sagnac interferometer. Our experiment proves that this platform can easily control the parameters related to double slits. In addition, a new, to the best of our knowledge, type of double-slit experiment is performed on the platform. Our approach provides a detailed conceptual and experimental analysis for wave-particle duality and will be useful for research on quantum optics.

The Invisible Reality of Quantum Mechanics: The ‎‎‎Deterministic Perspective

The fundamental deterministic nature of quantum mechanics (QM) is mathematically demonstrated by the modeling of the ‎‎‎quantum (multiple) slit experiments; hence this paper is written from a deterministic perspective (DP) in quantum mechanics.‎ ‎Due to approximately 90 years of indeterminism and probabilistic statistical results, the theory consists of many ‎‎‎interpretations and is often regarded as counterintuitive. The latter is in the deterministic perspective not the case and is ‎‎‎illustrated with some examples. After a brief historic perspective, ‘invisible’ i.e. invisible entities of reality in mathematical ‎‎‎treatment, are introduced. These entities are handled by mathematics indirectly i.e. are described in a transformed domain ‎‎‎without variables violating the Heisenberg relation. In nature, i.e. on micro and macro levels, causality is fully ‘entangled’ with ‎‎‎energy, information - in the meaning of ordering or coding - as well as time. In contrast with the macro scale with many forms ‎‎‎and types of memory functions, without a memory property of quanta, causality is the bearer of information symmetry on ‎‎the ‎quantum scale. Further on in this DP paper: mathematical and philosophical consequences and influences in several ‎‎‎paragraphs, regarding subjects such as ‘free will’ and expected ‘threats to science’, the Bell inequalities, Alice and Bob & ‎‎‎entanglement, causality, information, retro-causality, spooky action, encryption and computing, teleportation, and in general ‎‎‎interpretations rooted in indeterminacy in QM as well as associated topics on independence, fine-tuning. The last paragraph ‎‎‎outlines the mathematical treatment of QM more extensively and may clarify references to the above-mentioned topics of ‎‎‎discussion in QM further.‎

The contralateral organization of the human nervous system as a quantum unfolded, holographic-like, artifactual representation of the underlying dynamics of a fundamentally two-dimensional universe.

A working hypothesis is put forward in this article that the contralateral organization of the human nervous system appears to function like a quantum unfolded holographic apparatus by appearing to invert and reverse quantum unfolded visual and non-visual spatial information. As such, the three-dimensional contralateral organization would be an artifactual representation of the underlying dynamics of a fundamentally two-dimensional universe. According to the holographic principle, nothing that is experienced as three-dimensional could have been processed in a three-dimensional brain. Everything we would experience at a two-dimensional level would appear as a three-dimensional holographic representation, including the architecture of our brains. Various research observations reported elsewhere are reviewed and interpreted here as they may be related in a process that is fundamental to the underlying two-dimensional dynamics of the contralateral organization. The classic holographic method and characteristics of image formation contained by a holograph are described as they relate to the working hypothesis. The double-slit experiment is described and its relevance to the working hypothesis.

IYDSE: Ameliorated Young’s double-slit experiment optimizer for applied mechanics and engineering

The Young’s Double-Slit Experiment (YDSE) optimizer is a newly developed swarm intelligence algorithm inspired by Young’s double-slit experiment that reveals the wave nature of light. Due to its simple structure and efficiency, the researchers employed the algorithm to address real-world optimization problems in multiple domains. However, in large-scale mechanical and engineering applications, it still needs to balance exploration and exploitation effectively and easily fall into local optimum. Therefore, in order to ameliorate these shortcomings, a multi-strategy improved YDSE optimizer named IYDSE is developed in this study. In IYDSE, introducing the Bernoulli map strategy ensures a higher quality initial population in the initialization, thus improving the convergence speed. Then, Levy flight is utilized as a local development engine to avoid local search stagnation of the optimal solution during optimization. In addition, mirror reflection learning is designed to enhance group diversity. Finally, the information entanglement strategy is introduced to enhance the information exchange between light and dark fringes, thus balancing the exploration-development capability. The superiority of the proposed IYDSE is comprehensively demonstrated by comparing it with state-of-the-art algorithms on the CEC2019 and CEC2020 test suites, respectively. Meanwhile, the practicability of IYDSE is also verified by solving five specific engineering design cases and 50 different types of engineering optimization suites. Finally, the IYDSE algorithm is applied to three truss topology optimization problems. The experimental results demonstrate the applicability and development potential of the proposed algorithm in practical engineering applications. Therefore, IYDSE is potentially an effective and competitive algorithm for solving applied mechanics and engineering.

Entanglement-interference complementarity and experimental demonstration in a superconducting circuit

Quantum entanglement between an interfering particle and a detector for acquiring the which-path information plays a central role for enforcing Bohr’s complementarity principle. However, the quantitative relation between this entanglement and the fringe visibility remains untouched upon for an initial mixed state. Here we find an equality for quantifying this relation. Our equality characterizes how well the interference pattern can be preserved when an interfering particle, initially carrying a definite amount of coherence, is entangled, to a certain degree, with a which-path detector. This equality provides a connection between entanglement and interference in the unified framework of coherence, revealing the quantitative entanglement-interference complementarity. We experimentally demonstrate this relation with a superconducting circuit, where a resonator serves as a which-path detector for an interfering qubit. The measured fringe visibility of the qubit’s Ramsey signal and the qubit-resonator entanglement exhibit a complementary relation, in well agreement with the theoretical prediction.

Delayed-choice quantum erasure with nonlocal temporal double-slit interference

Wave–particle duality is a counterintuitive nature of quantum physics that challenges many common-sense assumptions, and Young’s double-slit interference is a prototypical example. While most quantum erasure experiments emphasized the choice of erasing or marking the which-path information of one quantum system, we use frequency entanglement to report a nonlocal temporal double-slit interferometer such that the which-time information determines the wave-like or particle-like behaviors. Since frequency-entangled photons are created simultaneously by using spontaneous parametric down conversion, the mark of temporal distinguishability is readily prepared by delaying one of the entangled photons, and its quantum eraser is implemented by using spectrally resolved detection with a tunable delayed choice. These results may provide an alternative aspect and insight into the role of the temporal degree in quantum-light complementarity and photon interference.

The Algebraic Approach: The Double Slit Experiment Explained

We present a new vision on the double-slit experiment (DSE) that does not use any waves or the so-called waveparticle duality. It is based on particles, viewed as localized vibrations. Rather than being illogical, or mysterious, the approach reproduces logically the interference patterns observed externally, using the well-known “amplification of stimulated emission” (ASE). The conservation of particle number is not observed. Different particles can present ASE with in-phase or counter phase behavior, making the patterns observed for electrons, other particles, even atoms. The Law of the Excluded Middle (LEM) is not broken illogically in two-states macroscopically, but broken naturally in three or more states, microscopically, using ASE. Any particle supporting ASE, in-phase or counter-phase, can enter a DSE, and provide an external interference pattern. Frequency plays a role, while amplitude is not considered. This work is important in quantum computing, possibly saving cost, time, and welcoming more participants.

A simulation method of gamma-ray phase contrast imaging for metal samples

Phase contrast imaging (PCI) for materials of low Z-index has been rapidly developed in recent years. And PCI is also considered to have great potential to improve the resolution of radiographic imaging of high-Z materials by using high-energy gamma-ray, but the research is still in its infancy. In this paper, we develop a simulation method of gamma-ray PCI, which is based on the combination of the Monte Carlo simulation and wave optics. The feasibility of this method is verified by comparing the simulation result of Young’s double-slit experiment with its analytic result. To demonstrate the potential of gamma-ray PCI, a simulation of a concentric metal sample is carried out. The edge enhancement effect of PCI is clearly observed at the interfaces of the sample. The simulation results preliminarily verify the feasibility of gamma-ray PCI for metallic materials.

Time domain double slit interference of electron produced by XUV synchrotron radiation

We present a new realization of the time-domain double-slit experiment with photoelectrons, demonstrating that spontaneous radiation from a bunch of relativistic electrons can be used to control the quantum interference of single-particles. The double-slit arrangement is realized by a pair of light wave packets with attosecond-controlled spacing, which is naturally included in the spontaneous radiation from two undulators in series. Photoelectrons emitted from helium atoms are observed in the energy-domain under the condition of detecting them one by one, and the stochastic buildup of the quantum interference pattern on a detector plane is recorded.

Effect of rotating target on speckle and orbital angular momentum characteristics of vector vortex beams

Based on angular spectrum diffraction theory, the scattering field of vector vortex beams (VVBs) passing through a rotating random rough surface is derived. The speckle produced by VVBs passing through the rotating ground glass is collected experimentally. The effects of ground glass roughness and rotational speed on the speckle and orbital angular momentum (OAM) of different order VVBs are discussed in detail. Furthermore, the speckle characteristics of the VVB are compared with the scalar vortex beam. The change in the OAM states of VVBs before and after passing through the rotating ground glass was detected by double-slit interference. The results show that the speckle of VVBs is generated after passing through the static ground glass, and the speckle contrast increases with the increment of roughness. Compared with the scalar vortex beam, the speckle contrast of the VVB changes faster with the roughness of ground glass. When the ground glass rotates, the speckle reduction effect appears and the contrast is reduced. When the rotational speed is >15 r / s, the speckle reduction effect is the strongest. The intensity distributions and OAM states of VVBs are not affected by the rotating ground glass. The research results provide a theoretical basis for the application of VVBs in optical communication, optical detection, and other fields.

Double-slit time diffraction at optical frequencies

Double-slit time diffraction at optical frequencies

An optical double-slit experiment in time

An optical double-slit experiment in time

A study discovered the coherent wave function of electrons and the stability when observed

The wave phase is the origin of creation and precedes the particulate (molecular) phase. The wave and particle are not two figures of the same thing, rather they are heterogeneous and different from each other due to the different sources of each of them. The particulate phase is just generated by impinging of the wave on its target of spatial forces (Higgs field), and the wave phase is considered the extra dimensions or the extended fuzzy end of the particle. Because electrons are forced to move in synchrony, they can produce heat and light. The light would be reflected from the electron forming many synchronized shadows for the same electron at different places that could be misinterpreted by both the instrumental detectors and the person analyzing the results of observations. Therefore, the electron cannot exist in different places, rather the shadows of the same electron give false observational results that produced the false analytic conclusion of “probability and randomness” and thus the term “superposition” is not scientifically consistent or coherent– The energy and momentum of electrons influence their motion through a material, which, in turn, determines its electrical and optical properties. – Using laser pulses, physicists have been able to generate hot electrons that travel faster than the speed of light. Regarding the electrons in the famous double-slit experiment, they are considered accelerated electrons, so their speed is faster than the speed of light. Because the light emitted from electrons and the light of the electron detector (ICCD camera) are electromagnetic waves, the speed of light emitted from electrons is faster than that of the detector. Consequently, the electron detector (ICCD camera) could detect the particle phase of electrons but couldn’t detect or capture the wave phase of electrons, because electromagnetic waves are harder to get a handle on. The result is the failure of observing and detecting the wave phase of electrons. Therefore, the wave function does not collapse.