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Nonclassical states are an important class of states in quantum mechanics, particularly for applications in quantum information theory. Optomechanical systems are invaluable platforms for exploring and harnessing these states. In this study, we focus on a mirror-in-the-middle optomechanical system. In the absence of losses, a separable state, composed of the product of coherent states, evolves into an entangled state. Furthermore, we demonstrate that generating a two-mode Schrödinger-cat state depends on the optomechanical coupling. Additionally, when the optical modes are uncoupled from the mechanical mode, we find no entanglement for certain nonzero optomechanical coupling intensities. We exactly solve the Gorini–Kossalokowinki–Sudarshan–Lindblad master equation, highlighting the direct influence of the reservoir on the dynamics when mechanical losses are considered. Then, we discuss vacuum one-photon superposition states to obtain exact entanglement dynamics using concurrence as a quantifier. Our results show that mechanical losses in the mirror attenuate the overall entanglement of the system. [ABSTRACT FROM AUTHOR]

A pedagogical introduction to Bell's inequality in Quantum Mechanics is presented. Several examples, ranging from spin 1 / 2 to coherent and squeezed states are worked out. The generalization to Mermin's inequalities and to GHZ states is also outlined. [ABSTRACT FROM AUTHOR]

Access to information can destroy nations and change the course of history altogether. Communication is very important, and in today's internet age, nothing moves without real-time information support. For securing communication, a commonly know technique is to use cryptography and public channels. Engineers have been working to create a better and more secure cryptographic system. Quantum key distribution stands at the top of this security system. Although QKD, based on principles of physics, provides a near-perfect security solution. It has a few drawbacks of its own, like low key generation rates and vulnerability to cyberattacks. Owning to these limitations, authors propose an adaptive quantum key distribution system based on software-defined networks. The authors propose to introduce redundancy in the key generation, thereby increasing the key generation rate and improving the resilience to cyberattacks. A performance comparison of novel quantum key distribution was done with BB84 and B92 quantum key distribution protocols. [ABSTRACT FROM AUTHOR]

Access to information can destroy nations and change the course of history altogether. Communication is very important, and in today's internet age, nothing moves without real-time information support. For securing communication, a commonly know technique is to use cryptography and public channels. Engineers have been working to create a better and more secure cryptographic system. Quantum key distribution stands at the top of this security system. Although QKD, based on principles of physics, provides a near-perfect security solution. It has a few drawbacks of its own, like low key generation rates and vulnerability to cyberattacks. Owning to these limitations, authors propose an adaptive quantum key distribution system based on software-defined networks. The authors propose to introduce redundancy in the key generation, thereby increasing the key generation rate and improving the resilience to cyberattacks. A performance comparison of novel quantum key distribution was done with BB84 and B92 quantum key distribution protocols.

Geometrical methods in quantum information are very promising for both providing technical tools and intuition into difficult control or optimization problems. Moreover, they are of fundamental importance in connecting pure geometrical theories, like GR, to quantum mechanics, like in the AdS/CFT correspondence. In this paper, we first make a survey of the most important settings in which geometrical methods have proven useful to quantum information theory. Then we lay down a geometric theory of entanglement by a principle of action, discussing a simple example with two qubits and consequences for a quantum theory of space-time. [ABSTRACT FROM AUTHOR]

We present a statistical simulation replicating the correlation observed in EPR coincidence experiments without needing non-local connectivity. We define spin coherence as a spin attribute that complements polarization by being anti-symmetric and generating helicity. Point particle spin becomes structured with two orthogonal magnetic moments, each with a spin of 1 2 —these moments couple in free flight to create a spin-1 boson. Depending on its orientation in the field, when it encounters a filter, it either decouples into two independent fermion spins of 1 2 , or it remains a boson and precedes without decoupling. The only variable in this study is the angle that orients a spin on the Bloch sphere, first identified in the 1920s. There are no hidden variables. The new features introduced in this work result from changing the spin symmetry from SU(2) to the quaternion group, Q8, which complexifies the Dirac field. The transition from a free-flight boson to a measured fermion causes the observed violation of Bell's Inequalities and resolves the EPR paradox. [ABSTRACT FROM AUTHOR]

Bell non-locality and steering are archetypal characteristics of quantum mechanics that mark a significant departure from conventional classical notions. They basically refer to the presence of quantum correlations between separated systems which violate a non-local inequality, the violation otherwise is not possible if we restrict ourselves only to classical correlations. In view of the importance of such unique correlations, one may be interested to generate more states exhibiting non-locality starting from a few, a protocol which is termed as broadcasting. However, in the present submission, we show using universal Buzek–Hillary (BH) quantum cloning machine that, if one restricts to broadcasting through local quantum cloning, then such non-locality cannot be broadcasted. Our study is done in the purview of the Bell-CHSH inequality and the CJWR [E G Cavalcanti et al, Phys. Rev. A80, 032112 (2009)] steering inequality. It is observed that when the number of measurement settings is greater than 6, some of the output states are steerable after the application of local optimal BH cloners. We found that, under some restrictions, if the Werner and Bell diagonal states are subjected to such procedures, then the resultant state is rendered unsteerable. We extended this study to three qubit systems and found that genuine tripartite non-locality cannot be broadcasted using universal BH local quantum cloners, when the Svetlichny's inequality was considered. For two qubit systems, we considered 10 5 simulated general local unitaries over Werner and Bell-diagonal states and found that for none of these states, broadcasting on non-locality and 3-steerability is possible. [ABSTRACT FROM AUTHOR]

This paper explains how the so-called Einstein locality is to be understood in the Schrödinger picture of quantum mechanics. This notion is fully compatible with the Bell non-locality exhibited by entangled states. Contrary to the belief that quantum mechanics is incomplete, it is, As a matter of fact, its overcompleteness, as exemplified by the different pictures of quantum physics, that points to the same underlying reality. [ABSTRACT FROM AUTHOR]

We derive the probability representation of even and odd cat states of two and three qubits. These states are even and odd superpositions of spin-1/2 eigenstates corresponding to two opposite directions along the z axis. The probability representation of even and odd cat states of an oscillating spin-1/2 particle is also discussed. The exact formulas for entangled probability distributions describing density matrices of all these states are obtained. [ABSTRACT FROM AUTHOR]

In this study, an effect that we will call entanglement closed loop (ECL) and that results from the implementation of entangled states through quantum Fourier transform (QFT) blocks, is presented. The dual-channel Bell test can be implemented using two linear polarizers (LP) or two half-wave plates (HWP). ECL allows us to verify that the arbitrary relocation of both the LPs and the HWPs is indifferent when it comes to reproducing the results of quantum mechanics. Implementations of two conspicuous relocations of the LPs on an optical table experimentally prove the existence of the entanglement closed loop. Finally, a new interpretation of quantum mechanics based on ECL, which explains the operation of a new family of quantum communications protocols, is presented. [ABSTRACT FROM AUTHOR]

Quantum Entanglement is one of the key manifestations of quantum mechanics that separate the quantum realm from the classical one. Characterization of entanglement as a physical resource for quantum technology became of uppermost importance. While the entanglement of bipartite systems is already well understood, the ultimate goal to cope with the properties of entanglement of multipartite systems is still far from being realized. This paper covers characterization of multipartite entanglement using algebraic-geometric tools. First, we establish an algorithm to classify multipartite entanglement by k -secant varieties of the Segre variety and ℓ -multilinear ranks that are invariant under Stochastic Local Operations with Classical Communication (SLOCC). We present a fine-structure classification of multiqubit and tripartite entanglement based on this algorithm. Another fundamental problem in quantum information theory is entanglement transformation that is quite challenging regarding to multipartite systems. It is captivating that the proposed entanglement classification by algebraic geometry can be considered as a reference to study SLOCC and asymptotic SLOCC interconversions among different resources based on tensor rank and border rank, respectively. In this regard, we also introduce a new class of tensors that we call persistent tensors and construct a lower bound for their tensor rank. We further cover SLOCC convertibility of multipartite systems considering several families of persistent tensors. [ABSTRACT FROM AUTHOR]

Both bosons and fermions satisfy a strong version of Leibniz's Principle of the Identity of Indiscernibles (PII), and so are ontologically on a par with respect to the PII. This holds for non-entangled, non-product states and for physically entangled states—as it has been established in previous work. In this paper, the Leibniz strategy is completed by including the (bosonic) symmetric product states. A new understanding of Pauli's Exclusion Principle is provided, which distinguishes bosons from fermions in a peculiar ontological way. Finally, the program as a whole is defended against substantial objections. [ABSTRACT FROM AUTHOR]

The aim of the paper is to investigate the role played by causality, and more specifically the no-signaling condition, in the assessment of the quantum theory. To this end, we discuss why it is important that even a non-relativistic theory such as Quantum Mechanics doesn’t imply a violation of this condition. Then, we use this argument to prove an original result stating that the destructive behaviour of the measurement process on the entanglement properties of quantum systems is a necessary and unavoidable feature of the quantum theory. Finally, we critically review the no-cloning theorem. The original formulation of the theorem states that a linear quantum cloning machine, designed in order to successfully clone states that coincide with appropriate basis vectors, fails to copy states that are a non-trivial superposition of those basis vectors; we will furthermore prove that such a linear cloning device, even with the hypothesis that it can only clone basis vectors successfully, may provide a violation of the no-signaling condition and therefore cannot exist.

The resource theory of imaginarity provides a valuable framework for understanding the role of complex numbers. Quantum channels play a vital role in extraction and transmission of information, and they can both destroy and create imaginarity in quantum states. In this article, we introduce the concepts of imaginaring and deimaginaring power of quantum channels to describe quantum channels' ability to create and destroy imaginarity. Furthermore, the imaginaring and deimaginaring power for several typical single-qubit channels based on l 1 norm, robustness and relative entropy of imaginarity were computed. In addition, we define the non-imaginarity-generating channel as the completely positive trace-preserving map which does not generate quantum imaginarity from an real state. Several properties of non-imaginarity-generating channels are investigated. Finally, we explore the trade-off relationship between imaginarity and entanglement. The relationship between the deimaginaring power of quantum channels based on relative entropy of the imaginarity and entanglement is studied. Additionally, we explore the creation of imaginarity in a bipartite state. We demonstrate that it is dependent on both the mixedness of initial system and the minimum amount of entanglement that can be created. Our work further studies imaginarity, which will contribute to the development of quantum mechanics and quantum techniques. [ABSTRACT FROM AUTHOR]

Much of our progress in understanding microscale biology has been powered by advances in microscopy. For instance, super-resolution microscopes allow the observation of biological structures at near-atomic-scale resolution, while multi-photon microscopes allow imaging deep into tissue. However, biological structures and dynamics still often remain out of reach of existing microscopes, with further advances in signal-to-noise, resolution and speed needed to access them. In many cases, the performance of microscopes is now limited by quantum effects – such as noise due to the quantisation of light into photons or, for multi-photon microscopes, the low cross-section of multi-photon scattering. These limitations can be overcome by exploiting features of quantum mechanics such as entanglement. Quantum effects can also provide new ways to enhance the performance of microscopes, such as new super-resolution techniques and new techniques to image at difficult to reach wavelengths. This review provides an overview of these various ways in which quantum techniques can improve microscopy, including recent experimental progress. It seeks to provide a realistic picture of what is possible, and what the constraints and opportunities are. [ABSTRACT FROM AUTHOR]

The idea that the key to life might be a quantum process is not new. Niels Bohr, Erwin Schrödinger, and Werner Heisenberg found signs of life at the quantum level. What they saw was useful, but not enough to solve the mystery of how life works. Two recent interpretations of quantum mechanics add new pieces to the puzzle: Quantum states act the same as what biologists call "anticipation" when the future possibilities of superposition states influence the outcome. And quantum wave function collapse acts the same way as what biologists call "purposeful actions" when a choice is made. This paper, the first in the series, "Opening Doors to a Quantum Theory of Life" (ODQTL), explores in detail the above two properties that are traditionally seen by biologists as being unique to life. In fact, many surprising traits of life are present at the quantum level. The idea that quanta might be alive is explored and shown to be a valid interpretation. A detailed theory of life is presented in Part 2 of this ODQTL series. It is published in this same issue of Integral Review (Marman, 2023b). The new theory explains how cellular life might have emerged from quantum processes. It offers a Catalyst-First Hypothesis and shows why catalysts might be the real drivers of life, not metabolism, RNA, or accidents such as lightning striking primordial soup. The new theory that emerges from this series of papers proposes that life is not based on the right combination of ingredients; it is a mutually responsive relationship between a life form and its habitat. We cannot take this relationship apart to study how life works because taking it apart kills the process of life. Quantum theory can explain this irreducible property as an entangled state, but new interpretations of quantum mechanics are needed to show why quantum principles must also be actively involved in relationships between organisms. This insight suggests that, when trying to understand life, context is more important than content. As a result, the science of quantum biology can expand to include interactions between organisms, opening doors that take us beyond quantum mechanics and chemistry, and perhaps even beyond biology to include psychology, as Heisenberg predicted. [ABSTRACT FROM AUTHOR]

This work compares the performance of single- and two-qubit probes for estimating several phase rotations simultaneously under the action of different noisy channels. We compute the quantum limits for this simultaneous estimation using collective and individual measurements by evaluating the Holevo and Nagaoka–Hayashi Cramér-Rao bounds, respectively. Several quantum noise channels are considered, namely the decohering channel, the amplitude damping channel, and the phase damping channel. For each channel, we find the optimal single- and two-qubit probes. Where possible we demonstrate an explicit measurement strategy that saturates the appropriate bound and we investigate how closely the Holevo bound can be approached through collective measurements on multiple copies of the same probe. We find that under the action of the considered channels, two-qubit probes show enhanced parameter estimation capabilities over single-qubit probes for almost all non-identity channels, i.e., the achievable precision with a single-qubit probe degrades faster with increasing exposure to the noisy environment than that of the two-qubit probe. However, in sufficiently noisy channels, we show that it is possible for single-qubit probes to outperform maximally entangled two-qubit probes. This work shows that, in order to reach the ultimate precision limits allowed by quantum mechanics, entanglement is required in both the state preparation and state measurement stages. It is hoped the tutorial-esque nature of this paper will make it easily accessible. [ABSTRACT FROM AUTHOR]

In this paper, we study the entanglement and quantum teleportation of a two-qutrit state evolved under one-axis counter-twisting Hamiltonian with the intrinsic decoherence effects. The entanglement and fidelity are analyzed as a function of decoherence rate, Hamiltonian coefficient, and magnetic field. It has been seen that the system is constantly entangled. Both the decoherence rate and the Hamiltonian coefficient have a negative correlation with the entanglement and fidelity. The faithfulness and negativity are efficiently optimized by the magnetic fields. We deduced that we can acquire some best fidelity for the system when it is maximally entangled. [ABSTRACT FROM AUTHOR]

We point out that, when the dimension of the Hilbert space is greater than two, Bell’s operators entering the Bell-CHSH inequality do exhibit inequivalent unitary matrix representations. Although the Bell-CHSH inequality turns out to be violated, the size of the violation is different for different representations, the maximum violation being given by Tsirelson’s bound. The feature relies on a pairing mechanism between the modes of the Hilbert space of the system. [ABSTRACT FROM AUTHOR]

This paper reconsiders what implications quantum decoherence has for Karen Barad’s agential realism. In contrast with the recent claim of Thomas Everth and Laura Gurney (2022), this paper argues that decoherence supports rather than defeats the holist, relational ontology of agential realism. Indeed, decoherence offers an explanation for how a quantum system can remain entangled and superposed in principle while it nevertheless in practice appears classical to a local observer. Decoherence shows why the appearance of classicality is not an objection to the ontology being in reality that of agential realism, in accordance with Barad’s repeated insistence that we should not mistake principle for practice. Whether users of agential realism in social theory should be encouraged by this is another matter that this paper does not take a stance on. As an ontology, however, agential realism is vindicated. [ABSTRACT FROM AUTHOR]

A short description of the notion of states of quantum systems in terms of conventional probability distribution function is presented. The notion and the structure of entangled probability distributions are clarified. The evolution of even and odd Schrödinger cat states of the inverted oscillator is obtained in the center-of-mass tomographic probability description of the two-mode oscillator. Evolution equations describing the time dependence of probability distributions identified with quantum system states are discussed. The connection with the Schrödinger equation and the von Neumann equation is clarified. [ABSTRACT FROM AUTHOR]

We explore the different notions of completeness applied in the EPR discussion following and amending the thorough analysis of Arthur Fine. To this aim, we propose a classification scheme for scientific theories that provides a methodology for analyzing the different levels at which interpretive approaches come into play. This allows us to contrast several concepts of completeness that operate on specific levels of the theory. We introduce the notion of theory completeness and compare it with the established notions of Born completeness, Schrödinger completeness and bijective completeness. We relate these notions to the recent concept of ψ -completeness and predictable completeness. The paper shows that the EPR argument contains conflicting versions of completeness. The confusion of these notions led to misunderstandings in the EPR debate and hindered its progress. Their clarification will thus contribute to recent debates on interpretational issues of quantum mechanics. Finally, we discuss the connection between the EPR paper and the Einstein–Rosen paper with regard to the question of completeness. [ABSTRACT FROM AUTHOR]

Both bosons and fermions satisfy a strong version of Leibniz’s Principle of the Identity of Indiscernibles (PII), and so are ontologically on a par with respect to the PII. This holds for non-entangled, non-product states and for physically entangled states—as it has been established in previous work. In this paper, the Leibniz strategy is completed by including the (bosonic) symmetric product states. A new understanding of Pauli’s Exclusion Principle is provided, which distinguishes bosons from fermions in a peculiar ontological way. Finally, the program as a whole is defended against substantial objections.

The essence of Newtonian mechanics is entanglement, which was inherited by quantum mechanics. Entanglement is a classical phenomenon based on the conservation of angular momentum and does not relate to quantization. Entanglement and propagation are the two wheels of physics. In this report, we show black hole mergers prove gravity entanglement. If we assume that gravity has a finite velocity, black holes are pulled slightly forward in the direction of travel, and gravity acts to accelerate the black holes; therefore, simulation conditions cannot be set, and we find that the assumption that gravity has a finite velocity is incorrect. This is because we cannot use the condition that the sum of kinetic and potential energies is constant. Gravity entanglement shows that entanglement continues permanently. Furthermore, Newtonian mechanics involves entanglement, ether, and equivalence principle. [ABSTRACT FROM AUTHOR]

The Nobel Prize in Physics 2022 has been awarded to John F. Clauser, Alain Aspect, and Anton Zeilinger, with each sharing 1/3rd of the prize. The prize has been awarded for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science. In this article, we aim to understand the physics and technologies behind the experiments that led to the prize. While each experimental contribution is seminal, we attempt to understand what makes them different from each other, what makes each of them unique, and how they have led to the burgeoning field of quantum science and technologies. [ABSTRACT FROM AUTHOR]

Can we accurately model the spin state of a quantum particle? If so, we should be able to make identical copies of such a state and also obtain its mirror image. In quantum mechanics, many subatomic particles can form entangled pairs that are mirror images of each other, although the state of an individual particle cannot be duplicated or cloned as experimentally demonstrated by Aspect, Clauser and Zeilinger, the winners of the Nobel Prize in Physics 2022. We show that there is a higher-order symmetry associated with the SL(2,C) group that underlies the singlet state, which means that the singlet pairing preserves Lorentz transformations independently of the metric used. The Pauli exclusion principle can be derived from this symmetry. [ABSTRACT FROM AUTHOR]

Quantum computing, based on the fundamental principles of quantum mechanics, has become a breakthrough that has the potential to revolutionize computing. At the forefront of this quantum revolution are quantum algorithms that use the origin of qubits to solve computational problems much faster than classical algorithms. This article provides a review of quantum algorithms to introduce their principles, examine famous examples such as the Grover and Shor algorithms, and delve into their applications, including quantum machine learning. Exploring the fundamentals of quantum computing begins with an overview that highlights the unique features of quantum computing compared to classical computing. We then examine several different algorithmic paradigms to highlight the unique advantages that quantum parallelism and interference bring to computing. The best knowledge of quantum algorithms focuses on Grover's blind search, Shor's efficient factorization algorithm, and the quantum phase approach for solving quantum chemistry and eigenvalue problems. As well as celebrating the achievements of quantum algorithms, this research also looks at the challenges and limitations that hinder their widespread use. Topics such as decoherence, error correction, and finding errors in quantum computing are discussed in the context of overcoming obstacles to the use of practical quantum algorithms. In addition, the latest developments are clarified by showing the successes of the experiments and their implications for the future. As we stand at the forefront of a new era in computing, this article not only provides a snapshot of the current state of quantum algorithms but also speculates on future directions. The potential applications of quantum algorithms in many fields and the ongoing quest to overcome current limitations offer exciting opportunities for further research. This research aims to contribute to the ongoing debate about quantum algorithms, gaining a deeper understanding of their impact on the future of computing. [ABSTRACT FROM AUTHOR]

Entanglement has become a hot topic in nuclear and particle physics, although many physicists are not sure they know what it means. We maintain that an era of understanding and using quantum mechanics on a dramatically new basis has arrived. We review a viewpoint that treats the subject as being primarily descriptive and completely free of the intellectual straitjackets and mysticism argued over long ago. Quantum probability is an extension of classical probability, but with universal uses. Density matrices describe systems where entanglement or its absence is a classification tool. Most of these have been known for decades, but there is a new way of understanding them that is liberated from the narrow outlook of the early days. [ABSTRACT FROM AUTHOR]

Geared as an invitation for undergraduates, beginning graduate students, we present a pedagogical introduction to one-dimen- sional topological phases—in particular, the Su-Schrieffer-Heeger model. In the process, we delve upon ideas of entangle- ment using the correlator method and the von-Neumann density-matrix method, geometric phase, polarization, transport signa- tures and the role of electron-electron interactions. Through hands-on numerical experiments, whose codes are shared, we try to drive home the message why a program of simulating quantum electronics with topological toy models is the store- house for discovering fantastic physics ideas. [ABSTRACT FROM AUTHOR]

Throughout quantum mechanics there is statistical balance, in the collective response of an ensemble of systems to differing measurement types. Statistical balance is a core feature of quantum mechanics, underlying quantum mechanical states, and not yet explained. The concept of "statistical balance" is here explored, comparing its meaning since 2019 with its original meaning in 2001. Statistical balance now refers to a feature of contexts in which: (a) there is a prescribed probability other than 0 or 1 for the collective response of an ensemble to one measurement type; and (b) the collective response of the same ensemble to another measurement type demonstrates that no well-defined value can be attributed, for the property relevant to the original measurement type, to individual members of the ensemble. In some unexplained way, the outcomes of single runs of a measurement of the original type "balance" each other to give an overall result in line with the prescribed probability. Unexplained statistical balance prompts caution in assessing the conceptual implications of entanglement, measurement, uncertainty, and two-slit and Bell-type analyses. Physicists have a responsibility to the wider population to be conceptually precise about quantum mechanics, and to make clear that many possible conceptual implications are uncertain. [ABSTRACT FROM AUTHOR]

Recently, interest has increased in the entanglement of remote quantum particles through the Newtonian gravitational interaction, both from a fundamental perspective and as a test case for the quantization of gravity. Likewise, post-Newtonian gravitational effects in composite nonrelativistic quantum systems have been discussed, where the internal energy contributes to the mass, promoting the mass to a Hilbert space operator. Employing a modified version of a previously considered thought experiment, it can be shown that both concepts, when combined, result in inconsistencies, reinforcing the arguments for the necessity of a rigorous derivation of the nonrelativistic limit of gravitating quantum matter from first principles. [ABSTRACT FROM AUTHOR]

Experiments witnessing the entanglement between two particles interacting only via the gravitational field have been proposed as a test whether gravity must be quantized. In the language of quantum information, a non-quantum gravitational force would be modeled by local operations with classical communication (LOCC), which cannot generate entanglement in an initially unentangled state. This idea is criticized as too constraining on possible alternatives to quantum gravity. We present a parametrized model for the gravitational interaction of quantum matter on a classical spacetime, inspired by the de Broglie–Bohm formulation of quantum mechanics, which results in entanglement and thereby provides an explicit counterexample to the claim that only a quantized gravitational field possesses this capability. [ABSTRACT FROM AUTHOR]

A new quantum mechanics mechanism theory based on statistical mechanics is introduced. This theory is based on corresponding changes in the number of states with associated energy changes at the observer and observed occurring at observer 1) reset and 2) observation. It is shown that a) the change in the number of states has different consequences than determining the “value” obtained at observation, where each state is a possible interaction between the system and the environment. The number of bits, as a measure of information content, is determined in discrete cell size increments. Two experiments are proposed to validate the introduced mechanism. The first experiment is to determine the spatial and temporal characteristics of energy changes and how they are related to the observer and observed during the entire measurement process. The second experiment is designed to determine timing between changes in the number of states in the system at observer reset. It is anticipated that these experiments will demonstrate no time delay, an entangled process, and, hence, explain delayed choice observations. Moreover, they would demonstrate that bits not stored in the system are transferred to the environment at observer reset, so when the number of inputs is greater than the number of outputs, an energy change occurs and interference is observed (wave characteristics). Conversely, if the number of inputs equals the number of outputs, no energy change occurs and no interference is observed (particle characteristics). It is envisioned that upon validating this mechanism theory, it will further the understanding of the measurement process and entanglement’s involvement in that process.

Quantum science is accelerating the transition from research to industrialized applications and scenarios, and its potential disruptive power in the development of future technological transformation, operational modes, and economy is emerging. In this study, we describe the state of the art of quantum science, and we attempt to provide an overview of quantum mechanics and its relevant prospects. On the other hand, we employ a certain tool (Biblioshiny from R Project) to analyze the relevant articles from Web of Science (WoS). The analysis shows that quantum science is an interdisciplinary field that is attracting more and more attention from both academia and practice. The application of quantum computer needs more time to be realized, it is potential to improve and change the whole society in many aspects. [ABSTRACT FROM AUTHOR]

What is known as the quantum measurement problem refers to the fact that in a measurement process the system becomes entangled with the measurement apparatus. As far as we know, this process has not been fully understood yet or characterized in know measurement models. Here, we study both the qualitative and quantitative entanglement arising in a generalized Arthurs–Kelly's model of simultaneous measurement, taking into account the full dynamical process (in a Gaussian configuration); hence, unlike the habitual strong coupling assumption, we consider the contribution of free energies in the Hamiltonian modeling the Arthurs–Kelly's measurement scheme. Under this dynamics, the quantum state becomes a three-mode entangled Gaussian state. Hence, using the positive partial transposed criterion, we certify the genuine tripartite entanglement by testing the separability of the three mode bipartition's of the system. Additionally, we quantify the entanglement by employing the minimum residual Gaussian contangle defined in (New J Phys 8(1):15, 2006; Phys Rev A 73(3):032345, 2006). Thus, we demonstrate that this simultaneous measurement scheme generates genuine multipartite entanglement. [ABSTRACT FROM AUTHOR]

Biological processes and physiological functions in living beings are featured by oscillations with a period of about 24 h (circadian) or cycle at the second and third harmonic (ultradian) of the basic frequency, driven by the biological clock. This molecular mechanism, common to all kingdoms of life, comprising animals, plants, fungi, bacteria, and protists, represents an undoubted adaptive advantage allowing anticipation of predictable changes in the environmental niche or of the interior milieu. Biological rhythms are the field of study of Chronobiology. In the last decade, growing evidence hints that molecular platforms holding up non-trivial quantum phenomena, including entanglement, coherence, superposition and tunnelling, bona fide evolved in biosystems. Quantum effects have been mainly implicated in processes related to electromagnetic radiation in the spectrum of visible light and ultraviolet rays, such as photosynthesis, photoreception, magnetoreception, DNA mutation, and not light related such as mitochondrial respiration and enzymatic activity. Quantum effects in biological systems are the field of study of Quantum Biology. Rhythmic changes at the level of gene expression, as well as protein quantity and subcellular distribution, confer temporal features to the molecular platform hosting electrochemical processes and non-trivial quantum phenomena. Precisely, a huge amount of molecules plying scaffold to quantum effects show rhythmic level fluctuations and this biophysical model implies that timescales of biomolecular dynamics could impinge on quantum mechanics biofunctional role. The study of quantum phenomena in biological cycles proposes a profitable "entanglement" between the areas of interest of these seemingly distant scientific disciplines to enlighten functional roles for quantum effects in rhythmic biosystems. [ABSTRACT FROM AUTHOR]

Human-centered systems of systems, such as social networks, the Internet of Things, or healthcare systems are growingly becoming significant facets of modern life. Realistic models of human behavior in such systems play an essential role in their accurate modeling and prediction. Nevertheless, human behavior under uncertainty often violates the predictions by the conventional probabilistic models. Recently, quantum-like decision theories have shown a considerable potential to explain the contradictions in human behavior by applying quantum probabilities. But providing a quantum-like decision theory that could predict rather than describe the current state of human behavior is still one of the unsolved challenges. The fundamental contribution of this work is introducing the concept of entanglement from quantum information theory to Bayesian networks (BNs). This concept leads to an entangled quantum-like BN (QBN), in which each human is a part of the entire society. Accordingly, society’s effect on the dynamic evolution of the decision-making process, which is less often considered in decision theories, is modeled by entanglement measures. To reach this aim, we introduce a quantum-like witness and find the relationship between this witness and the famous concurrence entanglement measure. The proposed predictive entangled QBN (PEQBN) is evaluated on 22 experimental tasks. Results confirm that PEQBN provides more realistic predictions of human decisions under uncertainty when compared with classical BNs and three recent quantum-like approaches. [ABSTRACT FROM AUTHOR]

Biological processes and physiological functions in living beings are featured by oscillations with a period of about 24 h (circadian) or cycle at the second and third harmonic (ultradian) of the basic frequency, driven by the biological clock. This molecular mechanism, common to all kingdoms of life, comprising animals, plants, fungi, bacteria, and protists, represents an undoubted adaptive advantage allowing anticipation of predictable changes in the environmental niche or of the interior milieu. Biological rhythms are the field of study of Chronobiology. In the last decade, growing evidence hints that molecular platforms holding up non-trivial quantum phenomena, including entanglement, coherence, superposition and tunnelling, bona fide evolved in biosystems. Quantum effects have been mainly implicated in processes related to electromagnetic radiation in the spectrum of visible light and ultraviolet rays, such as photosynthesis, photoreception, magnetoreception, DNA mutation, and not light related such as mitochondrial respiration and enzymatic activity. Quantum effects in biological systems are the field of study of Quantum Biology. Rhythmic changes at the level of gene expression, as well as protein quantity and subcellular distribution, confer temporal features to the molecular platform hosting electrochemical processes and non-trivial quantum phenomena. Precisely, a huge amount of molecules plying scaffold to quantum effects show rhythmic level fluctuations and this biophysical model implies that timescales of biomolecular dynamics could impinge on quantum mechanics biofunctional role. The study of quantum phenomena in biological cycles proposes a profitable “entanglement” between the areas of interest of these seemingly distant scientific disciplines to enlighten functional roles for quantum effects in rhythmic biosystems.

Definition: Quantum mechanics is a mathematical formalism that models the dynamics of physical objects. It deals with the elementary constituents of matter (atoms, subatomic and elementary particles) and of radiation. It is very accurate in predicting observable physical phenomena, but has many puzzling properties. The foundations of quantum mechanics are a domain in which physics and philosophy concur in attempting to find a fundamental physical theory that explains the puzzling features of quantum mechanics, while remaining consistent with its mathematical formalism. Several theories have been proposed for different interpretations of quantum mechanics. However, there is no consensus regarding any of these theories. [ABSTRACT FROM AUTHOR]

The unknown mechanism of wave-function collapse is called the measurement problem. The problem is best portrayed by a beam-split coincidence test, usually performed with visible light. The notion that energy conservation requires quantization is challenged by considering new beam-split tests and a threshold model (TM). An analysis of pulse heights in detectors for visible light concludes that their pulse height distribution is too broad to make the quantum/threshold distinction. This is because TM recognizes a preloaded state, understood in the loading theories of Planck, Debye, and Millikan, but usually unrecognized. The narrow pulse height distribution of gamma-ray detectors overcomes this detector problem. In addition, a source of singly emitted radiation is required for these beam-split tests. To assure a singly emitted source, the well-known true-coincidence test from nuclear physics is far more reliable than any test with visible light. One of my many successful beam-split coincidence tests with gamma-rays is described revealing the failure of quantum mechanics. After plotting the times between photoelectric effect pulses from the two detectors and comparing to accidental chance, I report a seemingly two-for-one effect that contradicts a photon kind of energy conservation. My similar tests performed with alpha-rays also contradict quantum mechanics. To explain how matter can load up, I hypothesize that our electron constants h, e, and m are maxima. Simple conserved ratios of these constants h/m, e/m, h/e, seen in equations involving electron beams, can explain how charge waves can spread, yet accumulate to measurable threshold values h, e, m, upon absorption to convey particle-like effects. [ABSTRACT FROM AUTHOR]

Einstein became bothered by quantum mechanical action at a distance within two years of Schrödinger's introduction of his eponymous wave equation. If the wave function represents the "real" physical state of a particle, then the measurement of the particle's position would result in the instantaneous collapse of the wave function to the single, measured position. Such a process seemingly violates not only the Schrödinger equation but also special relativity. Einstein was not alone in this vexation; however, the dilemma eventually faded as physicists concentrated on using the Schrödinger equation to solve a plethora of pressing problems. For the next 30 years, wave function collapse, while occasionally discussed by physicists, was primarily a topic of interest for philosophers. That is, until 1964, when Bell introduced his famous inequality and maintained that its violation proved that quantum mechanics and, by implication, nature herself are nonlocal. Unfortunately, this brought the topic back to mainstream physics, where it has remained and continues to muddy the waters. To be sure, not all physicists are bothered by the apparent nonlocality of quantum mechanics. So where have those who embrace quantum nonlocality gone wrong? I argue that the answer is a gratuitous belief in the ontic nature of the quantum state. [ABSTRACT FROM AUTHOR]

Certainly, a Smarandache multispace or multisystem eS is a union of m distinct spaces or systems S1; S2,..., Sm which is an appropriate model on things T in the universe because of the limitation of humans ourselves and a thing T is complex, even overlap with other things. However, nearly all observation data on T is a multiple one eS which implies Si and Sj are entangled if Si T Sj 6=;, we have to disentangle Si from Sj, 1 < i 6= j < m for hold on the reality of thing T. Thus, disentangling a multi-space eS to self-enclosed spaces or systems S1; S2,..., Sm is interesting, also valuable in hold on the reality of things in the universe. The main purpose of this paper is to discuss the disentangling ways on a Smarandache multispace or multisystem if we assume that each self-enclosed space or system of Si; 1 < i < m is endowed with mathematical elements such as those of topological, geometrical, algebraic structures or generally, each space or system of Si has a character i different from others for integers 1 < i < m. As it happens, this problem is equivalent to Schrodinger's cat of quantum mechanics in the case of m = 2, which are extensively applied in quantum teleportation for preparation, distribution and measurement of the entangled pairs of particles and prospecting us to design a general key carrier on the Smarandachely entangling pairs in commutation. [ABSTRACT FROM AUTHOR]

This paper aims to characterise properly entanglement as an external relation obtaining between multiple quantum degrees of freedom. In particular, we argue that the entanglement relation is a unique relation fully characterised by mutual information, i.e. a quantity standardly used as a measure of entanglement. This analysis leads us to propose a new metaphysical account of entanglement, which we call Relational Entanglement Tesseract. Such an account characterises entanglement for both bipartite and multipartite cases, and, at the same time, it satisfies what we argue are three important desiderata of any metaphysical account of entanglement. [ABSTRACT FROM AUTHOR]

The aim of the present article is to address the problem of entanglement in the case of indistinguishable particles from a perspective based on the algebraic formalism of quantum mechanics, which is the natural formal counterpart of an ontology of properties, devoid of the ontological category of object. On the basis of this perspective, an algebraic definition of entanglement is adopted, which supplies a unified conception, valid for both the distinguishable and the indistinguishable cases. An additional advantage of this algebraic definition is that it does justice to the relativity of entanglement, a feature that cannot be ignored. [ABSTRACT FROM AUTHOR]

We explore the different notions of completeness applied in the EPR discussion following and amending the thorough analysis of Arthur Fine. To this aim, we propose a classification scheme for scientific theories that provides a methodology for analyzing the different levels at which interpretive approaches come into play. This allows us to contrast several concepts of completeness that operate on specific levels of the theory. We introduce the notion of theory completeness and compare it with the established notions of Born completeness, Schrödinger completeness and bijective completeness. We relate these notions to the recent concept of ψ-completeness and predictable completeness. The paper shows that the EPR argument contains conflicting versions of completeness. The confusion of these notions led to misunderstandings in the EPR debate and hindered its progress. Their clarification will thus contribute to recent debates on interpretational issues of quantum mechanics. Finally, we discuss the connection between the EPR paper and the Einstein–Rosen paper with regard to the question of completeness.