The double slit interference experiment has been famously described by Richard Feynman as containing the "only mystery of quantum mechanics". The history of quantum mechanics is intimately linked with the discovery of the dual nature of matter and radiation. While the double slit experiment for light is easily undertsood in terms of its wave nature, the very same experiment for particles like the electron is somewhat more difficult to comprehend. By the 1920s it was firmly established that electrons have a wave nature. However, for a very long time, most discussions pertaining to interference experiments for particles were merely gedanken experiments. It took almost six decades after the establishment of its wave nature to carry out a 'double slit interference' experiment for electrons. This set the stage for interference experiments with larger particles. In the last decade there has been spectacular progress in matter-wave interefernce experiments. Today, molecules with over a hundred atoms can be made to interfere. In the following we discuss some of these exciting developments which probe new regimes of Nature, bringing us closer to the heart of quantum mechanics and its hidden mysteries.
The double slit interference experiment has been famously described by Richard Feynman as containing the "only mystery of quantum mechanics". The history of quantum mechanics is intimately linked with the discovery of the dual nature of matter and radiation. While the double slit experiment for light is easily undertsood in terms of its wave nature, the very same experiment for particles like the electron is somewhat more difficult to comprehend. By the 1920s it was firmly established that electrons have a wave nature. However, for a very long time, most discussions pertaining to interference experiments for particles were merely gedanken experiments. It took almost six decades after the establishment of its wave nature to carry out a 'double slit interference' experiment for electrons. This set the stage for interference experiments with larger particles. In the last decade there has been spectacular progress in matter-wave interefernce experiments. Today, molecules with over a hundred atoms can be made to interfere. In the following we discuss some of these exciting developments which probe new regimes of Nature, bringing us closer to the heart of quantum mechanics and its hidden mysteries.
Quantum mechanics has fundamentally changed the way scientists think about the world. Quantum mechanical theory has found it's way into our everyday lives through advances in technology. In this dissertation a fundamental quantum mechanical demonstration and the technological development of a new quantum mechanical device are presented. Double-slit diffraction is a corner stone of quantum mechanics. It illustrates key features of quantum mechanics: interference and the particle-wave duality of matter. Here we demonstrate the full realization of Richard Feynman's famous thought experiment. By placing a movable mask in front of a double-slit to control the transmission through the individuals slits. Probability distributions for single- and double-slit arrangements were observed. Additionally, by recording single electron detection events diffracting through a double-slit,a diffraction pattern was built up from individual events. Additionally, a demonstration of a three grating Talbot-Lau interferometer for electrons is presented. As a proof of principle the interferometer is used to measure magnetic fields. The possibility to extend this work to build a scaled-up electron interferometer for sensitive magnetic field sensing is discussed. A theoretical model is presented to simulate the two experiments. This model is developed from Richard Feynman's path integral formalism, where a wave function is propagated through the elements of the system. The theoretical simulations reproduce the experimental data well, except for a large discrepancy of a factor of 5.5 between the experimental and theoretical sensitivity of the Talbot-Lau interferometer. The origin of the discrepancy is currently unknown. These experiments were built off of previous work done here at the University of Nebraska-Lincoln, and improvements to the preexisting system are discussed. While these experiments likely did not demonstrate anything contrary to conventional quantum mechanics, it is important to continually probe these types of experiments to test the fundamental principles of quantum mechanics and explore it's technical applications. Advisor: Herman Batelaan
Science, as it is generally described at school, starts with experimental data. Scientists then have to find some hypothesis which explains these results. Using this hypothesis, a prediction is made about what might happen in a slightly different experiment. The double-slit experiment is a modified version of the setup first used by Thomas Young in 1801. Young’s version is a classic experiment that, at the time, seemed to have settled the dispute between wave and particle views of light decisively in favour of waves. The idea that particles might display some wavelike properties dates to the mid-1920s when a young PhD student called Louis De Broglie was thinking about the dual wave/particle nature of light. A quantum mechanical description of the double-slit experiment must involve a set of amplitudes governing the passage of an electron through the slits to the far detector.
The classical interpretation of Young’s double slit experiment is that, before and after passing through the diaphragm of the double slit, the light behaves as waves. Feynman called the double slit experiment “the only mystery [of quantum mechanics]. We have shown for the first time that in the classical wave experiments: (1) Particle patterns, which are non-interference patterns indicating the particle nature of light, are near the diaphragm, and Interference patterns are near the screen; (2) Particle patterns evolve to Transition patterns that are also non-interference patterns, and, finally, evolve to Interference patterns; (3) Postulates of lens for utilizing lens in wave experiments. blob:https://www.techrxiv.org/615e9312-3e89-48d5-99fe-bbad6cef8a75 blob:https://www.techrxiv.org/4fad8e66-75e1-47db-af51-d9e445461b9b blob:https://www.techrxiv.org/e4274387-92e5-41bb-9185-038555bb2f13 In this article, we experimentally show that Particle patterns, Transition patterns and Interference patterns of the double slit experiments are simultaneously emerged on the screen. We suggest that these phenomena and the physical mechanism of photons distributing as waves are new mystery.
The classical interpretation of Young’s double slit experiment is that, before and after passing through the diaphragm of the double slit, the light behaves as waves. Feynman called the double slit experiment “the only mystery [of quantum mechanics]. We have shown for the first time that in the classical wave experiments: (1) Particle patterns, which are non-interference patterns indicating the particle nature of light, are near the diaphragm, and Interference patterns are near the screen; (2) Particle patterns evolve to Transition patterns that are also non-interference patterns, and, finally, evolve to Interference patterns; (3) Postulates of lens for utilizing lens in wave experiments. blob:https://www.techrxiv.org/615e9312-3e89-48d5-99fe-bbad6cef8a75 blob:https://www.techrxiv.org/4fad8e66-75e1-47db-af51-d9e445461b9b blob:https://www.techrxiv.org/e4274387-92e5-41bb-9185-038555bb2f13 In this article, we experimentally show that Particle patterns, Transition patterns and Interference patterns of the double slit experiments are simultaneously emerged on the screen. We suggest that these phenomena and the physical mechanism of photons distributing as waves are new mystery.
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.
Abstract One of the greatest mysteries that has puzzled and seemingly hoodwinked our very understanding of nature is the single electron double slit experiment – one that Feynman termed the central mystery of quantum mechanics. At the heart of this mystery is how can an electron that is a physical particle exhibit a wave-like property? We’ve proposed a non-counterintuitive way to explain this phenomenon called the randomly-jumping electron hypothesis, in which the electron randomly “jumps” in discrete succession to specific points only and not others which is what causes the electron to indeed be a classical particle only but is able to produce a wave-like interference pattern. To provide supporting evidence for our hypothesis, we’ve developed a computer program to simulate the single electron double slit experiment by treating the electron as a classical particle while still exhibiting wave-like fringes in agreement with real-world observed data of the single electron double slit experiment performed. Our interpretation does not set out to “solve” the mystery of why an electron can produce a wave-like interference pattern once and for all, however our hypothesis is a monism ontological interpretation that does address some of the crucial debates that have remained unsolved for 100 years since the formulation of quantum mechanics.