Foundations Of Quantum Mechanics Research Articles

The Principle and Application Prospect of Optical Temperature Measurement

The principle of optical thermometry not only changes the cognition of deterministic worldview in classical physics but also lays an important foundation for quantum mechanics. The challenge is still to reach places that are difficult to reach or that have an impact on the measurement environment. In this paper, the physical meaning of the principle of optical thermometry and its application and research progress in modern physics are reviewed. The fundamental limitation in quantum measurement is revealed. In this paper, the principle of temperature measurement is based on the characteristic that the emission spectrum of the excited fluorescent material changes with the temperature. The most important characteristic of fluorescence spectrum temperature measurement is that it overcomes the limitations of traditional temperature measurement. In this paper, the basic theory of blackbody radiation, especially Planck’s law radiation, is briefly introduced and the close relationship between radiant energy and temperature is emphasized. In the third part, Raman spectroscopy and its basic principle are studied. The last part of this paper focuses on the temperature measurement method’s in-depth study of its principle and application. The theoretical basis of the method, including the radiation law and optical properties, is described in detail. The photometric temperature measurement method has a wide application prospect in the fields of industrial production process monitoring, fire early warning, scientific research experiments, and so on. Future research can further optimize the photometric temperature measurement technology, improve its adaptability and reliability, and provide more effective means for temperature measurement.

Entangling Independent Particles by Path Identity.

Quantum entanglement-correlations of particles that are stronger than any classical analog-is the basis for research on the foundations of quantum mechanics and for practical applications such as quantum networks. Traditionally, entanglement is achieved through local interactions or via entanglement swapping, where entanglement at a distance is generated through previously established entanglement and Bell-state measurements. However, the precise requirements enabling the generation of quantum entanglement without traditional local interactions remain less explored. Here, we demonstrate that independent particles can be entangled without the need for direct interaction, prior established entanglement, or Bell-state measurements, by exploiting the indistinguishability of the origins of photon pairs. Our demonstrations challenge the long-standing belief that the prior generation and measurement of entanglement are necessary prerequisites for generating entanglement between independent particles that do not share a common past. In addition to its foundational interest, we show that this technique might lower the resource requirements in quantum networks, by reducing the complexity of photon sources and the overhead photon numbers.

Is the Wavefunction Already an Object on Space?

Since the discovery of quantum mechanics, the fact that the wavefunction is defined on the 3n-dimensional configuration space rather than on the 3-dimensional space has seemed uncanny to many, including Schrödinger, Lorentz, and Einstein. Even today, this continues to be seen as a significant issue in the foundations of quantum mechanics. In this article, it will be shown that the wavefunction is, in fact, a genuine object on space. While this may seem surprising, the wavefunction does not possess qualitatively new features that were not previously encountered in objects known from Euclidean geometry and classical physics. The methodology used involves finding equivalent reinterpretations of the wavefunction exclusively in terms of objects from the geometry of space. The result is that we will find the wavefunction to be equivalent to geometric objects on space in the same way as was always the case in geometry and physics. This will be demonstrated to hold true from the perspective of Euclidean geometry, but also within Felix Klein’s Erlangen Program, which naturally fits into the classification of quantum particles by the representations of spacetime isometries, as realized by Wigner and Bargmann, adding another layer of confirmation. These results lead to clarifications in the debates about the ontology of the wavefunction. From an empirical perspective, we already take for granted that all quantum experiments take place in space. I suggest that the reason why this works is that they can be interpreted naturally and consistently with the results presented here, showing that the wavefunction is an object on space.

Bohr versus Einstein

Abstract Niels Bohr and Albert Einstein were extraordinarily famous physicists who feuded in the early days of quantum mechanics. Their debate was really a clash between two opposing conceptions of the foundations of quantum mechanics. These views were also debated by many other people. So it is not so much their debate as a clash of views of which they were the most prominent proponents. This paper will begin by introducing the opponents and then give an overview of the events and the opposing standpoints, roughly characterised as “local realism” and “operationalism”. It will then follow the course of the debate in three rounds.

Role of Fourier transform in quantum mechanics: applications and implications

The Fourier transform, as a fundamental mathematical tool, plays a pivotal role in quantum mechanics. Its significance extends to wave function analysis, solving the Schrdinger equation, and elucidating the relationship between position and momentum. In this review article, the primary objective is to summarize the diverse applications of the Fourier transform in quantum mechanics. This paper will delve into key applications, highlighting the uncertainty principle, the Planck-Einstein relation, and the Fourier transform solution of the Schrdinger equation. These theorems and relationships not only facilitate the mathematical manipulation of quantum states but also lay the theoretical foundation of quantum mechanics. By exploring these critical aspects, the author aims to provide a comprehensive understanding of how the Fourier transform underpins the core principles of quantum theory, offering valuable insights into the wave particle duality and the probabilistic nature of quantum systems. This discussion will emphasize the essential nature of the Fourier transform in both theoretical development and practical problem-solving within quantum mechanics

Incompatible observables in classical physics: A closer look at measurement in Hamiltonian mechanics.

Quantum theory famously entails the existence of incompatible measurements, pairs of system observables which cannot be simultaneously measured to arbitrary precision. Incompatibility is widely regarded to be a uniquely quantum phenomenon, linked to failure to commute of quantum operators. Even in the face of deep parallels between quantum commutators and classical Poisson brackets, no connection has been established between the Poisson algebra and any intrinsic limitations to classical measurement. Here I examine measurement in classical Hamiltonian physics as a process involving the joint evolution of an object-system and a finite-temperature measuring apparatus. Instead of the ideal measurement capable of extracting information without disturbing the system, I find a Heisenberg-like precision-disturbance relation: Measuring an observable leaves all Poisson-commuting observables undisturbed but inevitably disturbs all non-Poisson-commuting observables. In this classical uncertainty relation the role of h-bar is played by an apparatus-specific quantity, q-bar. While this is not a universal constant, the analysis suggests that q-bar takes a finite positive value for any apparatus that can be built. (Specifically: q-bar vanishes in the model only in the unreachable limit of zero absolute temperature.) I show that a classical version of Ozawa's model of quantum measurement [Ozawa, Phys. Rev. Lett. 60, 385 (1988)0031-900710.1103/PhysRevLett.60.385], originally proposed as a means to violate Heisenberg's relation, does not violate the classical relation. If this result were to generalize to all models of measurement, then incompatibility would prove to be a feature not only of quantum, but of classical physics too. Put differently: The approach presented here points the way to studying the (Bayesian) epistemology of classical physics, which was until now assumed to be trivial. It now seems possible that it is nontrivial and bears a resemblance to the quantum formalism. The present findings may be of interest to researchers working on foundations of quantum mechanics, particularly for ψ-epistemic interpretations. More practically, there may be applications in the fields of precision measurement, nanoengineering, and molecular machines.

Cosmos MIND and matter: Is mind in spacetime?

We attempt in this article to formulate a conceptual and testable framework weaving Cosmos, Mind and Matter into a whole. We build on three recent discoveries, each requiring more evidence: i. The particles of the Standard Model, SU(3) x SU(2) x U(1), are formally capable of collective autocatalysis. This leads us to ask what roles such autocatalysis may have played in Cosmogenesis, and in trying to answer, Why our Laws? Why our Constants? A capacity of the particles of SU(3) x SU(2) x U(1) for collective autocatalysis may be open to experimental test, stunning if confirmed. ii. Reasonable evidence now suggests that matter can expand spacetime. The first issue is to establish this claim at or beyond 5 sigma if that can be done. If true, this process may elucidate Dark Matter, Dark Energy and Inflation and require alteration of Einstein's Field Equations. Cosmology would be transformed. iii. Evidence at 6.49 Sigma suggests that mind can alter the outcome of the two-slit experiment. If widely and independently verified, the foundations of quantum mechanics must be altered. Mind plays a role in the universe. That role may include Cosmic Mind. OUR CONSIDERATIONS CONCERN: 1. Ontologically Real Potentia and the Unmanifest; 2. Nonlocality as Fundamental; 3. Res potentia, Res extensa, and Actualization; 4. Mind and Qualia, Mind is not in Spacetime; 5. Quantum Vacuum=Potentia not in Spacetime=Mind not in Spacetime; 6. Mind can Actualize Potentia; 7. The emergence of the classical world; 8. Co-evolution of evermore complex matter; 9. Why "My Mind"?; 10. Each embodied mind is coupled bilaterally to the Quantum Vacuum that is Cosmic Mind; 11. Responsible Free Will.

Tightrope-Walking Rationality in Action: Feyerabendian Insights for the Foundations of Quantum Mechanics

ABSTRACT We scan Paul K. Feyerabend's work in philosophy of physics and of science more generally for insights that could be useful for the contemporary debate on the foundations of quantum mechanics. We take as our starting point what Feyerabend has actually written about quantum mechanics, but we extend our analysis to his general views on realism, objectivity, pluralism, and the relation between physics and philosophy, finding that these more general views could in fact offer many interesting insights for physicists and philosophers working on quantum foundations.

Conference “Two Days of History and Epistemology of the Foundations of Quantum Mechanics”

Conference “Two Days of History and Epistemology of the Foundations of Quantum Mechanics”

Exploring the Foundations of Quantum Mechanics: Recent Developments and Open Questions

Exploring the Foundations of Quantum Mechanics: Recent Developments and Open Questions

The Second Quantum Revolution: Unexplored Facts and Latest News

The Second Quantum Revolution refers to a contemporary wave of advancements and breakthroughs in the field of quantum physics that extends beyond the early developments of Quantum Mechanics that occurred in the 20th century. One crucial aspect of this revolution is the deeper exploration and practical application of quantum entanglement. Entanglement serves as a cornerstone in the ongoing revolution, contributing to quantum computing, communication, fundamental physics experiments, and advanced sensing technologies. Here, we present and discuss some of the recent applications of entanglement, exploring its philosophical implications and non-locality beyond Bell’s theorem, thereby critically examining the foundations of Quantum Mechanics. Additionally, we propose educational activities that introduce high school students to Quantum Mechanics by emphasizing entanglement as an essential concept to understand in order to become informed participants in the Second Quantum Revolution. Furthermore, we present the state-of-art developments of a largely unexplored and promising realization of real qubits, namely the molecular spin qubits. We review the available and suggested device architectures to host and use molecular spins. Moreover, we summarize the experimental findings on solid-state spin qubit devices based on magnetic molecules. Finally, we discuss how the Second Quantum Revolution might significantly transform law enforcement by offering specific examples and methodologies to address the evolving challenges in public safety and security.

On Defining a Living Element as an Increment of Wave Energy to an Existing Particle-wave

This paper overall treats the timeless mind-body problem. Descartes said: “I think, therefore I am.” This suggests the existence of life in a non-material world, specifically, a spacetime that is devoid of particles, which then evokes the equally celebrated theme of the wave-particle duality, which is the foundation of quantum mechanics. Correspondingly in mathematics, there is a dichotomy of the real number 1, and the imaginary number i - - which has however presented itself as a mystery for centuries. Here, we maintain that a 1-dimensional manifold is either a line or otherwise with curvatures and any curvature can be locally fitted by a circle, i.e., either a line with unit 1 or a unit circle expressed by exp(it), such as in the contrast between a linear calendar time t and a circular clock time it, or a linear expansion versus a rotational motion as indicated by the eigenvalues of a linear operator in a dynamical system. As such, the imaginary number i is just a periodic motion, or a wave. While Maxwell’s electromagnetic wave has energy, the quantum wave is yet a probability; we unify these two treatments of the wave by equating the quantum wave with Maxwell’s electromagnetic wave. The wave-particle duality logically leads to a diagonal spacetime manifold containing {(particle, its associated electromagnetic wave)}. In literature, a particle wave has its energy E distributed into (3E/4, E/4) respectively. Experimentally, a 50/50 beam splitter has been found to split half of the E/4 into a particle-less wave, evidencing the existence of a separate but coincidental wave universe; it is here that we define a living element as a set of particle-less electromagnetic waves that adds life to a set of molecules in the particle universe. We will present the mathematical formulation of the above and examine its implications and applications.

Research and prospects of encryption mechanism for quantum communication

With the continuous advancement of quantum communication technology, the public's interest in quantum mechanics and quantum communication has been steadily increasing. However, due to the general level of knowledge and misleading popular science videos on the internet, there are significant misconceptions regarding the understanding of quantum mechanics and quantum communication technology. This study aims to enhance readers' understanding of this field by providing an accessible introduction to the fundamentals of quantum mechanics and quantum communication. This paper starts by elaborating on the basic concepts of quantum mechanics, such as wave function, eigenvalues and eigenfunctions of observables, and the superposition of eigenstates. Then, taking polarization of light as an example, the fundamental principles of quantum mechanics are explained. Subsequently, through the examples of the BB84 and B92 protocols, the working principles of quantum communication and its advantage of being secure against eavesdropping are explained. Finally, an overview of the current status and technological challenges faced by quantum communication technology is provided. It is our expectation that readers, after reading this paper, will enhance their understanding of the theoretical foundations of quantum mechanics and quantum communication, thereby avoiding being misled by erroneous information from the internet and real-life sources.

Quantum-to-Classical Coexistence: Wavefunction Decay Kinetics, Photon Entanglement, and Q-Bits

By utilizing a generalized version of the Madelung quantum hydrodynamic framework that incorporates noise, we derive a solution using the path integral method to investigate how a quantum superposition of states evolves over time. This exploration seeks to comprehend the process through which a stable quantum state emerges when fluctuations induced by the noisy gravitational background are present. The model defines the conditions that give rise to a limited range of interactions for the quantum potential, allowing for the existence of coarse-grained classical descriptions at a macroscopic level. The theory uncovers the smallest attainable level of uncertainty in an open quantum system and examines its consistency with the localized behavior observed in large-scale classical systems. The research delves into connections and similarities alongside other theories such as decoherence and the Copenhagen foundation of quantum mechanics. Additionally, it assesses the potential consequences of wave function decay on the measurement of photon entanglement. To validate the proposed theory, an experiment involving entangled photons transmitted between detectors on the moon and Mars is discussed. Finally, the findings of the theory are applied to the creation of larger Q-bit systems at room temperatures.

Digital Discovery of 100 diverse Quantum Experiments with PyTheus

Photons are the physical system of choice for performing experimental tests of the foundations of quantum mechanics. Furthermore, photonic quantum technology is a main player in the second quantum revolution, promising the development of better sensors, secure communications, and quantum-enhanced computation. These endeavors require generating specific quantum states or efficiently performing quantum tasks. The design of the corresponding optical experiments was historically powered by human creativity but is recently being automated with advanced computer algorithms and artificial intelligence. While several computer-designed experiments have been experimentally realized, this approach has not yet been widely adopted by the broader photonic quantum optics community. The main roadblocks consist of most systems being closed-source, inefficient, or targeted to very specific use-cases that are difficult to generalize. Here, we overcome these problems with a highly-efficient, open-source digital discovery framework PyTheus, which can employ a wide range of experimental devices from modern quantum labs to solve various tasks. This includes the discovery of highly entangled quantum states, quantum measurement schemes, quantum communication protocols, multi-particle quantum gates, as well as the optimization of continuous and discrete properties of quantum experiments or quantum states. PyTheus produces interpretable designs for complex experimental problems which human researchers can often readily conceptualize. PyTheus is an example of a powerful framework that can lead to scientific discoveries – one of the core goals of artificial intelligence in science. We hope it will help accelerate the development of quantum optics and provide new ideas in quantum hardware and technology.

Invariant Model of Boltzmann Statistical Mechanics and its Implications to Hydrodynamic Model of Electromagnetism, Physical Foundations of Quantum Mechanics, Relativity, Quantum Gravity and Quantum Cosmology

Invariant Model of Boltzmann Statistical Mechanics and its Implications to Hydrodynamic Model of Electromagnetism, Physical Foundations of Quantum Mechanics, Relativity, Quantum Gravity and Quantum Cosmology

Quantum mechanics as a theory that is consistent with the existence of God

I sketch the foundation of quantum mechanics as it is presented in various books and articles. Then a new approach to quantum foundation is described, a foundation that relies on 4 simple postulates related to the mind of an observer or to the joint minds of a group of communicating observers. One of these postulates may appear to be strong, but it turns out to be more natural when it is placed in a religious setting. This assumes the existence of an omnipotent God. These arguments are further discussed, and they are shown also to give a foundation of Quantum Decision Theory.

On the possibility of a real reform in current physics: Penrose and twistor theory

Since the late 1960s, Roger Penrose has had the ambition to develop a new theory that rethinks the foundations of quantum mechanics. His twistor theory aims to carry out this difficult task. Although today the theory is still in development, it is no less true that it is finding more and more followers and its results are beginning to seem not as far-fetched as initially believed. The goal is still far away, but his impetus for wanting to change things is still valid.

Study on the Diffraction-like and Interference-like Mechanisms of Particle Flow

This paper demonstrates that the light and dark fringe in Young's double-slit experiment is not actually the diffraction and interference pattern of light wave. We investigate the scattering phenomenon after the particle flow passes through the gaps and find that the scattering type and scattering degrees of freedom of the particle flow depend on the physical parameters of the particles and the gaps. When the particle flow undergoes uniform scattering, a uniform "yes" and "no" interspersed discrete distribution pattern will form on the receiving screen. Based on the diffraction-like and interference-like mechanism of particle flow, this paper explains the electron diffraction and interference experiment, as well as the Young's double-slit interference experiment and the diffraction of light through circular holes and plates. This article provides an in-depth discussion on Einstein's concept of wave particle duality and de Broglie's matter wave hypothesis, as well as an analysis of Feynman's experimental idea of electron double slit interference. Our research shows that the matter wave hypothesis is not valid, which has shaken the foundation of modern quantum mechanics and has significant scientific significance. In addition, this study has important application value for the development of technology for detecting and analyzing particles or gaps.

Gleason’s theorem for composite systems

Gleason’s theorem (Gleason 1957 J. Math. Mech. 6 885) is an important result in the foundations of quantum mechanics, where it justifies the Born rule as a mathematical consequence of the quantum formalism. Formally, it presents a key insight into the projective geometry of Hilbert spaces, showing that finitely additive measures on the projection lattice extend to positive linear functionals on the algebra of bounded operators . Over many years, and by the effort of various authors, the theorem has been broadened in its scope from type I to arbitrary von Neumann algebras (without type factors). Here, we prove a generalisation of Gleason’s theorem to composite systems. To this end, we strengthen the original result in two ways: first, we extend its scope to dilations in the sense of Naimark (1943 Dokl. Akad. Sci. SSSR 41 359) and Stinespring (1955 Proc. Am. Math. Soc. 6 211) and second, we require consistency with respect to dynamical correspondences on the respective (local) algebras in the composition (Alfsen and Shultz 1998 Commun. Math. Phys. 194 87). We show that neither of these conditions changes the result in the single system case, yet both are necessary to obtain a generalisation to bipartite systems.