Can quantum communication be more efficient than its classical counterpart? Holevo's theorem rules out the possibility of communicating more than n bits of classical information by the transmission of n quantum bits—unless the two parties are entangled, in which case twice as many classical bits can be communicated but no more. In apparent contradiction, there are distributed computational tasks for which quantum communication cannot be simulated efficiently by classical means. In some cases, the effect of (...) transmitting quantum bits cannot be achieved classically short of transmitting an exponentially larger number of bits. In a similar vein, can entanglement be used to save on classical communication? It is well known that entanglement on its own is useless for the transmission of information. Yet, there are distributed tasks that cannot be accomplished at all in a classical world when communication is not allowed, but that become possible if the non-communicating parties share prior entanglement. This leads to the question of how expensive it is, in terms of classical communication, to provide an exact simulation of the spooky power of entanglement. (shrink)

In a recent paper, we describe how a model of quantum communication based on combining consciousness experiment and entanglement can serve as impetus to stop 5G-caused diseases. Therefore, in this paper we will discuss how entanglement can be explained in terms of quantum theory. This short review may be considered as an effort to bring QM into real problem solving, i.e. telecommunication.

Quantum entanglement has been focus of fundamental debate since the original paper of Einstein, Podolsky and Rosen [1] and the work of Bell [2], discussing its implications on fundamental issues related to the concepts of physical reality and locality. It has only been during the last few years when it has been recognized that this feature of Quantum Mechanics may also have important applications in the fields of communication and computation. In particular, it has been shown that (...) using entanglement would allow to perform certain computational tasks, such as factoring, much faster. On the other hand, it provides the basis for provably secure secret communication and cryptography. (shrink)

The paper explores the fundamental physical principles of quantum mechanics (in fact, quantum field theory) that limit the bit rate for long distances and examines the assumption used in this exploration that losses can be ignored. Propagation of photons in optical fibers is modelled using methods of quantum electrodynamics. We define the “photon duration” as the standard deviation of the photon arrival time; we find its asymptotics for long distances and then obtain the main result of the (...) paper: the linear dependence of photon duration on the distance when losses can be ignored. This effect puts the limit to joint increasing of the photon flux and the distance from the source and it has consequences for quantum communication. Once quantum communication develops into a real technology (including essential decrease of losses in optical fibres), it would be appealing to engineers to increase both the photon flux and the distance. And here our “photon flux/distance effect” has to be taken into account. This effect also may set an additional constraint to the performance of a loophole free test of Bell’s type—to close jointly the detection and locality loopholes. (shrink)

It is a frequent assumption that—via superluminal information transfers—superluminal signals capable of enabling communication are necessarily exchanged in any quantum theory that posits hidden superluminal influences. However, does the presence of hidden superluminal influences automatically imply superluminal signalling and communication? The non-signalling theorem mediates the apparent conflict between quantum mechanics and the theory of special relativity. However, as a ‘no-go’ theorem there exist two opposing interpretations of the non-signalling constraint: foundational and operational. Concerning Bell’s theorem, we (...) argue that Bell employed both interpretations, and that he finally adopted the operational position which is associated often with ontological quantum theory, e.g., de Broglie–Bohm theory. This position we refer to as “effective non-signalling”. By contrast, associated with orthodox quantum mechanics is the foundational position referred to here as “axiomatic non-signalling”. In search of a decisive communication-theoretic criterion for differentiating between “axiomatic” and “effective” non-signalling, we employ the operational framework offered by Shannon’s mathematical theory of communication, whereby we distinguish between Shannon signals and non-Shannon signals. We find that an effective non-signalling theorem represents two sub-theorems: Non-transfer-control theorem, and Non-signification-control theorem. Employing NTC and NSC theorems, we report that effective, instead of axiomatic, non-signalling is entirely sufficient for prohibiting nonlocal communication. Effective non-signalling prevents the instantaneous, i.e., superluminal, transfer of message-encoded information through the controlled use—by a sender-receiver pair —of informationally-correlated detection events, e.g., in EPR-type experiments. An effective non-signalling theorem allows for nonlocal quantum information transfer yet—at the same time—effectively denies superluminal signalling and communication. (shrink)

Quantum Counterfactual Communication is the recently-proposed idea of using quantum physics to send messages between two parties, without any matter/energy transfer associated with the bits sent. While this has excited massive interest, both for potential ‘unhackable’ communication, and insight into the foundations of quantum mechanics, it has been asked whether this process is essentially quantum, or could be performed classically. We examine counterfactual communication, both classical and quantum, and show that the protocols (...) proposed so far for sending signals that don’t involve matter/energy transfer associated with the bits sent must be quantum, insofar as they require wave-particle duality. (shrink)

We introduce a two-party communication complexity problem in which the probability of success by using a particular strategy allows the parties to detect with certainty whether or not some forbidden communication has taken place. We show that theprobability of success is bounded by nature; any conceivable method which gives a probability of success outside these bounds is impossible. Moreover, any conceivable method to solve the problem which gives a probability success within these bounds is possible in nature. This (...) example suggests that a suitaby chosen set of communication complexity problems could be the basis of an information-theoretic axiomatization of quantum mechanics. (shrink)

This paper focuses on stakeholder identification as per the value sensitive design (VSD) approach applied to the context of quantum technologies (QT). We provide two comprehensive lists of stakeholders as starting points for VSD researchers and practitioners. These lists encompass a diverse range of organizations, including private companies, government agencies, NGOs, partnerships, and professional/trade organizations. Our aim is to facilitate the recognition, legitimation, and understanding of stakeholder interactions in the development of QT. These stakeholder lists can serve as a (...) foundation for designing and implementing policies and strategies that promote the ethical and responsible development of QT, considering the values and interests of various stakeholders. Furthermore, these lists can enable empirical and technical studies on specific QT innovations using an ethics-by-design approach like VSD. Overall, this paper contributes to a better understanding of the complex and dynamic nature of the QT landscape and highlights the importance of stakeholder engagement and collaboration in shaping its future. (shrink)

The relation between quantum collapse, consciousness and superluminal communication is analyzed. As we know, quantum collapse, if exists, can result in the appearance of quantum nonlocality, and requires the existence of a pre- ferred Lorentz frame. This may permit the realization of quantum superluminal communication (QSC), which will no longer result in the usual causal loop in case of the existence of a preferred Lorentz frame. The possibility of the existence of QSC is further (...) analyzed under the assumption that quantum collapse is a real process. We demonstrate that the combination of quantum collapse and the consciousness of the observer will permit the observer to distinguish nonorthogonal states in principle. This provides a possible way to realize QSC. Some implications of the existence of QSC are briefy discussed. (shrink)

Twenty five years ago, Sir John Carew Eccles together with Friedrich Beck proposed a quantum mechanical model of neurotransmitter release at synapses in the human cerebral cortex. The model endorsed causal influence of human consciousness upon the functioning of synapses in the brain through quantum tunneling of unidentified quasiparticles that trigger the exocytosis of synaptic vesicles, thereby initiating the transmission of information from the presynaptic towards the postsynaptic neuron. Here, we provide a molecular upgrade of the Beck and (...) Eccles model by identifying the quantum quasiparticles as Davydov solitons that twist the protein α-helices and trigger exocytosis of synaptic vesicles through helical zipping of the SNARE protein complex. We also calculate the observable probabilities for exocytosis based on the mass of this quasiparticle, along with the characteristics of the potential energy barrier through which tunneling is necessary. We further review the current experimental evidence in support of this novel bio-molecular model as presented. (shrink)

It is assumed that experiments yield results that are not isomorphic with reality, but represent a distorted image of reality. Reality is related to observation via a communication channel of finite capacity. Quantum uncertainties are due to the bound on the amount of information available. Use is made of recent results from information and communication theories.

Given the collapse hypothesis (CH) of quantum measurement, EPR-type correlations along with the hypothesis of the impossibility of superluminal communication (ISC) have the effect of globalizing gross features of the quantum formalism making them universally true. In particular, these hypotheses imply that state transformations of density matrices must be linear and that evolution which preserves purity of states must also be linear. A gedanken experiment shows that Lorentz covariance along with the second law of thermodynamics imply a (...) nonentropic version of ISC. Partial results using quantum logic suggest, given ISC and a version of CH, a connection between Lorentz covariance and the covering law. These results show that standard quantum mechanics is structurally unstable, and suggest that viable relativistic alternatives must question CH. One may also speculate that some features of the Hilbert-space model of quantum mechanics have their origin in space time structure. (shrink)

”Quantum entanglement”, a phrase first coined by Erwin Schr¨ odinger1, describes a condition of the separated parts of the same quantum system in which each of the parts can only be described by referencing the state of other part. This is one of the most counterintuitive aspects of quantum mechanics, because classically one would expect system parts out of speed-of-light contact to be completely independent. Thus, entanglement represents a kind of quantum connectedness in which measurements on (...) one isolated part of an entangled quantum system have non-classical consequences for the outcome of measurements performed on the other (possibly very distant) part of the same system. This quantum connectedness that enforces the measurement correlation and state-matching in entangled quantum systems has come to be called quantum nonlocality. (shrink)

The FLASH communicator consists of an apparatus which can distinguish between plane unpolarized (PUP) and circularly unpolarized (CUP) light plus a simple EPR arrangement. FLASH exploits the peculiar properties of “measurements of the Third Kind.” One purpose of this article is to focus attention on the operation of idealized laser gain tubes at the one-photon limit.

With the emergence of quantum technologies such as quantum computing, quantum communications, and quantum sensing, new potential has emerged for smart manufacturing and Industry 4.0. These technologies, however, present ethical concerns that must be addressed in order to ensure they are developed and used responsibly. This article outlines some of the ethical challenges that quantum technologies may raise for Industry 4.0 and presents the value sensitive design methodology as a strategy for ethics-by-design of quantum (...) computing in Industry 4.0. This research further investigates the potential ethical difficulties that may come from the use of quantum technologies in Industry 4.0, such as concerns about privacy, security, accountability, and the influence of these technologies on workers and society as a whole. The article argues, based on current literature, that these issues necessitate a proactive and comprehensive approach to ethics-by-design. (shrink)

A possible mechanism of nonlinear quantum evolution is introduced and its implications for quantum communication are investigated. First, it is demonstrated that an appropriate combination of wavefunction collapse and the consciousness of observer may permit the observer to distinguish nonorthogonal quantum states in principle, and thus consciousness will introduce certain nonlinearity into quantum dynamics. Next, it is shown that the distinguishability of nonorthogonal states can be used to achieve quantum superluminal communication, by which (...) information can be transmitted nonlocally and faster than the speed of light. Finally, the issue of apparent incompatibility between superluminal communication and special relativity is briefly addressed. (shrink)

A correction to this paper has been published: doi:10.1007/s10701-021-00450-z.

Quantum information processing is at the crossroads of physics, mathematics and computer science. It is concerned with what we can and cannot do with quantum information that goes beyond the abilities of classical information processing devices. Communication complexity is an area of classical computer science that aims at quantifying the amount of communication necessary to solve distributed computational problems. Quantum communication complexity uses quantum mechanics to reduce the amount of communication that would (...) be classically required.Pseudo-telepathy is a surprising application of quantum information processing to communication complexity. Thanks to entanglement, perhaps the most nonclassical manifestation of quantum mechanics, two or more quantum players can accomplish a distributed task with no need for communication whatsoever, which would be an impossible feat for classical players. After a detailed overview of the principle and purpose of pseudo-telepathy, we present a survey of recent and not-so-recent work on the subject. In particular, we describe and analyse all the pseudo-telepathy games currently known to the authors. (shrink)

This edited collection provides new perspectives on some metaphysical questions arising in quantum mechanics. These questions have been long-standing and are of continued interest to researchers and graduate students working in physics, philosophy of physics and metaphysics. It features contributions from a diverse set of researchers, ranging from senior scholars to junior academics, working in varied fields, from physics to philosophy of physics and metaphysics. The contributors reflect on issues about fundamentality (is quantum theory fundamental? If so, what (...) is its fundamental ontology?), ontological dependence (how do ordinary objects exist even if they are not fundamental?), realism (what kind of realism is compatible with quantum theory?), indeterminacy (can the world itself exhibit ontological indeterminacy?). With contributions from both physicists (including Nobel Prize winner Gerard 't Hooft), science communicators and philosophers. (shrink)

Quantum mechanics is currently being tried to be used as a probe to unravel the mysteries of consciousness. Present paper deals with this probe, quantum mechanics and its usefulness in getting an insight of working of human consciousness. The formation of quantum mechanics based on certain axioms, its development to study the dynamical behavior and motions of fundamental particles and quantum energy particles moving with the velocity of light, its insistence on wave functions, its probability approach, (...) its dependence on uncertainty principles will all be critically discussed. The result of this discussion will be presented. Its limitations in unraveling the form, function and biological nature of consciousness will be presented. The alternative probe available and being used – the translation of Upanishadic insight and Advaita philosophy into cognitive science elements in delineating the definition, form and function of Consciousness will be given. The usefulness of this modeling and analysis in understanding the consciousness, mind and its functions in cognitive science and theory of human language acquisition and communication will also be presented. The physic-chemical nature of ideas, senses, thoughts, feelings, utterances will be grossly dealt with. The functions of consciousness and mind, in knowledge and language acquisition and communication will be dealt with. (shrink)

The purpose of this article is threefold. Firstly, it aims to present, in an educational and non-technical fashion, the main ideas at the basis of Aerts’ creation-discovery view and hidden measurement approach : a fundamental explanatory framework whose importance, in this author’s view, has been seriously underappreciated by the physics community, despite its success in clarifying many conceptual challenges of quantum physics. Secondly, it aims to introduce a new quantum machine—that we call the δ quantum machine —which (...) is able to reproduce the transmission and reflection probabilities of a one-dimensional quantum scattering process by a Dirac delta-function potential. The machine is used not only to demonstrate the pertinence of the above mentioned explanatory framework, in the general description of physical systems, but also to illustrate (in the spirit of Aerts’ ∊-model) the origin of classical and quantum structures, by revealing the existence of processes which are neither classical nor quantum, but irreducibly intermediate. We do this by explicitly introducing what we call the k-model and by proving that its processes cannot be modelized by a classical or quantum scattering system. The third purpose of this work is to exploit the powerful metaphor provided by our quantum machine, to investigate the intimate relation between the concept of potentiality and the notion of non-spatiality , that we characterize in precise terms, introducing for this the new concept of process-actuality. (shrink)

This paper provides a brief introduction to quantum theory and the proceeds to discuss the different ways in which the relationship between quantum theory and mind/consciousness is seen in some of the main alternative interpretations of quantum theory namely by Bohr; von Neumann; Penrose: Everett; and Bohm and Hiley. It briefly considers how qualia might be explained in a quantum framework, and makes a connection to research on quantum biology, quantum cognition and quantum (...) computation. The paper notes that it is widely agreed that conscious experience has dynamical and holistic features. It asks whether these features might in some way be a reflection of the dynamic and holistic quantum physical processes associated with the brain that may underlie (and make possible) the more mechanistic neurophysiological processes that contemporary cognitive neuroscience is measuring. If so, these macroscopic processes would be a kind of shadow, or amplification of the results of quantum processes at a deeper (pre-spatial or "implicate") level where our minds and conscious experience essentially live and unfold. The macroscopic, mechanistic level is of course necessary for communication, cognition and life as we know it, including science; but perhaps the experiencing (consciousness) of that world and the initiation of our actions takes place at a more subtle, non-mechanical level of the physical world, which quantum theory has begun to discover. At the very least a quantum perspective will help a “classical” consciousness theorist to become better aware of some of the hidden assumptions in his or her approach. Given that consciousness is widely thought to be a “hard” problem, its solution may well require us to question and revise some of our assumptions that now seem to us completely obvious. This is what quantum theory is all about – learning, on the basis of scientific experiments, to question the “obvious” truths about the nature of the physical world and to come up with more coherent alternatives. (shrink)

"The Quantum Revelation is mind-blowing." --Sting To say that quantum physics is the greatest scientific discovery of all time is not an exaggeration. In their discovery of the quantum realm, the physics community stumbled upon a genuine multifaceted revelation which can be likened to a profound spiritual treasure--a heretofore undreamed of creative power--hidden within our own mind. Quantum physics unequivocally points out that the study of the universe and the study of consciousness are inseparably linked, which (...) is to say that ultimate progress in the one will be impossible without progress in the other. Einstein declared that what it reveals is so immensely important that "it should be everyone's concern." Yet few of us in the general public truly understand how the game-changing discoveries of the past century not only relate to our day-to-day lives, but also give us insights into the nature of reality and our place within it. Written for readers with no physics background, Paul Levy's latest book, The Quantum Revelation: A Radical Synthesis of Science and Spirituality is for those who have heard that quantum physics is a fascinating subject but don't quite understand how or why. Levy contemplates the deeper philosophical underpinnings of quantum physics, exploring the fundamental questions it provokes: What does it mean that quantum theory has discovered that there is no such thing as "objective reality?" How are we participating--via our consciousness--in creating our experience of a reality that quantum theory itself describes as "dreamlike?" What are the implications for us in our day-to-day lives that--as quantum theory reveals--what we call reality is more like a dream that we had previously imagined? The Quantum Revelation is unique in how it synthesizes science and spirituality so as to reveal and explore the dreamlike nature of reality. It is a book not just for people interested in quantum theory, but for anyone who is interested in waking up and dreaming lucidly, be it in our night dreams or our waking life. (shrink)

This book provides the first unified overview of the burgeoning research area at the interface between Quantum Foundations and Quantum Information. Topics include: operational alternatives to quantum theory, information-theoretic reconstructions of the quantum formalism, mathematical frameworks for operational theories, and device-independent features of the set of quantum correlations. Powered by the injection of fresh ideas from the field of Quantum Information and Computation, the foundations of Quantum Mechanics are in the midst of a (...) renaissance. The last two decades have seen an explosion of new results and research directions, attracting broad interest in the scientific community. The variety and number of different approaches, however, makes it challenging for a newcomer to obtain a big picture of the field and of its high-level goals. Here, fourteen original contributions from leading experts in the field cover some of the most promising research directions that have emerged in the new wave of quantum foundations. The book is directed at researchers in physics, computer science, and mathematics and would be appropriate as the basis of a graduate course in Quantum Foundations. (shrink)

While its applications have made quantum theory arguably the most successful theory in physics, its interpretation continues to be the subject of lively debate within the community of physicists and philosophers concerned with conceptual foundations. This situation poses a problem for a pragmatist for whom meaning derives from use. While disputes about how to use quantum theory have arisen from time to time, they have typically been quickly resolved, and consensus reached, within the relevant scientific sub-community. Yet rival (...) accounts of the meaning of quantum theory continue to proliferate . In this article I offer a diagnosis of this situation and outline a pragmatist solution to the problem it poses, leaving further details for subsequent articles. (shrink)

"Science is rooted in conversations," wrote Werner Heisenberg, one of the twentieth century's great physicists. In Quantum Dialogue, Mara Beller shows that science is rooted not just in conversation but in disagreement, doubt, and uncertainty. She argues that it is precisely this culture of dialogue and controversy within the scientific community that fuels creativity. Beller draws her argument from her radical new reading of the history of the quantum revolution, especially the development of the Copenhagen interpretation. One of (...) several competing approaches, this version succeeded largely due to the rhetorical skills of Niels Bohr and his colleagues. Using extensive archival research, Beller shows how Bohr and others marketed their views, misrepresenting and dismissing their opponents as "unreasonable" and championing their own not always coherent or well-supported position as "inevitable." Quantum Dialogue, winner of the 1999 Morris D. Forkosch Prize of the Journal of the History of Ideas, will fascinate everyone interested in how stories of "scientific revolutions" are constructed and "scientific consensus" achieved. "[A]n intellectually stimulating piece of work, energised by a distinct point of view."—Dipankar Home, Times Higher Education Supplement "[R]emarkable and original. . . . [Beller's] arguments are thoroughly supported and her conclusions are meticulously argued. . . . This is an important book that all who are interested in the emergence of quantum mechanics will want to read."—William Evenson, History of Physics Newsletter. (shrink)

It has long been thought that observing distinctive traces of quantum gravity in a laboratory setting is effectively impossible, since gravity is so much weaker than all the other familiar forces in particle physics. But the quantum gravity phenomenology community today seeks to do the (effectively) impossible, using a challenging novel class of `tabletop' Gravitationally Induced Entanglement (GIE) experiments, surveyed here. The hypothesized outcomes of the GIE experiments are claimed by some (but disputed by others) to provide a (...) `witness' of the underlying quantum nature of gravity in the non-relativistic limit, using superpositions of Planck-mass bodies. We inspect what sort of achievement it would possibly be to perform GIE experiments, as proposed, ultimately arguing that the positive claim of witness is equivocal. Despite various sweeping arguments to the contrary in the vicinity of quantum information theory or given low-energy quantum gravity, whether or not one can claim to witness the quantum nature of the gravitational field in these experiments decisively depends on which out of two legitimate modelling paradigms one finds oneself in. However, by situating GIE experiments in a tradition of existing experiments aimed at making gravity interestingly quantum in the laboratory, we argue that, independently of witnessing or paradigms, there are powerful reasons to perform the experiments, and that their successful undertaking would indeed be a major advance in physics. (shrink)

The purpose of this book is to initiate a new discipline, namely a formalized epistemological method drawn from the cognitive strategies practised in the most effective among the modern scientific disciplines, as well as from general philosophical thinking. Indeed, what is lacking in order to improve our knowledge and our domination of the modes which nowadays are available for the generation and communication of knowledge, thoroughly and rapidly and with precision and detail? It is a systematic explication of the (...) epistemological essence encrypted in the specialized languages and algorithms of the major modern scientific approaches, a systematic cross-referencing of the explicated results, and a final elaboration of a new coherent whole. Quantum mechanics, like a diver, can take us down to the level of the very first actions of our conceptualization of reality. And starting from there, it can induce an explicit understanding of certain fundamental features of the new scientific thinking. A formalized epistemology should not be mistaken for a crossdisciplinary or a multidisciplinary project. The latter projects are designed to offer to nonspecialists access to information, to results obtained inside specialized disciplines, as well as a certain understanding of these results; whereas a formalized epistemology should equip anyone with a framework for conceptualizing himself in whatever domain and direction he or she might choose. A formalized epistemology should not be mistaken either for an approach belonging to the modern cognitive sciences. These try to establish as neutrally as possible descriptions of how the human body-and-mind work spontaneously when knowledge is generated; whereas a method of conceptualization should establish what conceptual-operational deliberate procedures have to be applied in order to represent and to achieve processes of generation of knowledge optimized accordingly to any definite aims. This book addresses philosophers of science, physicists, mathematicians, logicians, computer scientists, researchers in cognitive sciences, and biologists, as well as any intellectual who is interested in scientific and philosophical thinking. (shrink)

This work seeks to explain intuitive perception - those perceptions that are not based on reason or logic or on memories or extrapolations from the past, but are based, instead, on accurate foreknowledge of the future. Often such intuitive foreknowledge involves perception of implicit information about nonlocal objects and/or events by the body's psychophysiological systems. Recent experiments have shown that intuitive perception of a future event is related to the degree of emotional significance of that event, and a new study (...) shows that both the brain and the heart are involved in processing a pre-stimulus emotional response to the future event. Drawing on this research and on the principles of quantum holography, I develop a theory of intuition that views the perception of things remote in space or ahead in time (nonlocal communication) as involving processes of energetic resonance connecting the body's psychophysiological systems to the quantum level. The theory explains how focused emotional attention directed to the nonlocal object of interest attunes the bio-emotional energy generated by the body's psychophysiological systems to a domain of quantum-holographical information, which contains implicit information about the object. The body's perception of such implicit information about things distant in space/time is experienced as an intuition. (shrink)

The essence of temporal universe creation is that any analytical solution has to comply with the boundary condition of our universe; dimensionality and causality constraints. The essence of this book is to show that everything has a price within our temporal (t > 0) universe; energy and time.

There exists a growing literature on the so-called physical Church-Turing thesis in a relativistic spacetime setting. The physical Church-Turing thesis is the conjecture that no computing device that is physically realizable can exceed the computational barriers of a Turing machine. By suggesting a concrete implementation of a beyond-Turing computer in a spacetime setting, Istvan Nemeti and Gyula David have shown how an appreciation of the physical Church-Turing thesis necessitates the confluence of mathematical, computational, physical, and indeed cosmological ideas. In this (...) essay, I will honour Istvan's seventieth birthday, as well as his longstanding interest in, and his seminal contributions to, this field going back to as early as 1987 by modestly proposing how the concrete implementation in Nemeti and D\'avid might be complemented by a quantum-information-theoretic communication protocol between the computing device and the logician who sets the beyond-Turing computer a task such as determining the consistency of Zermelo-Fraenkel set theory. This suggests that even the foundations of quantum theory and, ultimately, quantum gravity may play an important role in determining the validity of the physical Church-Turing thesis. (shrink)

A recent no-go theorem (Frauchiger and Renner in Nat Commun 9(1):3711, 2018) establishes a contradiction from a specific application of quantum theory to a multi- agent setting. The proof of this theorem relies heavily on notions such as ‘knows’ or ‘is certain that’. This has stimulated an analysis of the theorem by Nurgalieva and del Rio (in: Selinger P, Chiribella G (eds) Proceedings of the 15th international conference on quantum physics and logic (QPL 2018). EPTCS 287, Open Publishing (...) Association, Waterloo, 2018), in which they claim that it shows the “[i]nadequacy of modal logic in quantum settings” (ibid.). In this paper, we will offer a significantly extended and refined reconstruction of the theorem in multi-agent modal logic. We will then show that a thorough reconstruction of the proof as given by Frauchiger and Renner requires the reflexivity of access relations (system T). However, a stronger theorem is possible that already follows in serial frames, and hence also holds in systems of doxastic logic (such as KD45). After proving this, we will discuss the general implications for different interpretations of quantum probabilities as well as several options for dealing with the result. (shrink)

This book gives an overview for practitioners and students of quantum physics and information science. It provides ready access to essential information on quantum information processing and communication, such as definitions, protocols and algorithms. Quantum information science is rarely found in clear and concise form. This book brings together this information from its various sources. It allows researchers and students in a range of areas including physics, photonics, solid-state electronics, nuclear magnetic resonance and information technology, in (...) their applied and theoretical branches, to have this vital material directly at hand. (shrink)

The surprising aspects of quantum information are due to two distinctly non-classical features of the quantum world: first, different quantum states need not be orthogonal and, second, quantum states may be entangled. Non-orthogonality leads to the blurring of classical distinctions. On the other hand, entanglement leads via non-locality to teleportation and other ``entanglement-assisted'' forms of communication that go beyond what is classically possible. In this article we attempt to understand these new possibilities via an analysis (...) of the significance of entanglement for the basic physical concepts of a ``particle'' and a ``localized physical system''. Classical particles can be individuated on the basis of qualitative differences in their sets of properties. But in entangled states the ``particle labels'' of the quantum formalism usually do not pick out such sets of individuating particle properties. It is sometimes nevertheless possible to think in terms of individual particles, which may be localized; but we argue that in general the structure of quantum mechanics is at odds with such a particle interpretation. This finally leads us to the conclusion that quantum mechanics is best seen as not belonging to the category of space-time theories, in which physical quantities are functions on space-time points. The resulting picture of the quantum world is relevant for our understanding of the way in which quantum theory is non-local, and it sheds light on the novel aspects of quantum information. (shrink)

EPR experiments demonstrate that standard quantum mechanics exhibits the property of nonlocality , the enforcement of correlations between separated parts of an entangled quantum systems across spacelike separations. Nonlocality will be clarified using the transactional interpretation of quantum mechanics, and the possibility of superluminal effects (e.g., faster-than-light communication) from nonlocality and non-linear quantum mechanics will be examined.

Quantum cryptography makes use of the quantum-mechanical behavior of nature for the design and analysis of cryptographic schemes. Optimally (but not always), quantum cryptography allows for the design of cryptographic schemes whose security is guaranteed solely by the laws of nature. This is in sharp contrast to standard cryptographic schemes, which can be broken in principle, i.e., when given sufficient computing power. From a theory point of view, quantum cryptography offers a beautiful interplay between the mathematics (...) of adversarial behavior and quantum information theory. In this review article, we discuss the traditional application of quantum cryptography, quantum key distribution (QKD), from a modern perspective, and we discuss some recent developments in the context of quantum two-party cooperation (2PC). QKD allows two distant parties to communicate in a provably-secure way in the presence of an outside eavesdropper, whereas 2PC is concerned with protecting information against possibly malicious insiders. We show the basic idea of constructing quantum cryptographic schemes, but we also show some connections to quantum information theory as needed for the rigorous security analyses, and we discuss some of the relevant quantum-information-theoretic results. (shrink)

The authors undertake a thought experiment the purpose of which is to explore possibilities for understanding moral principles in analogy with cosmic order. The experiment is based on three proposals, which are described in detail: an ontological, a neurological, and a moral proposal. The ontological proposal accepts from the phenomena of quantum physics that there is a nonempirical domain of physical reality that consists not of material things but of what is philosophically conceptualized as a realm of nonmaterial forms. (...) This realm of forms is the realm of potentiality in physical reality that quantum physics posits as an indivisible Wholeness—the One. It is the ultimate reality because everything empirical is the actualization of its forms. The neurological proposal is the hypothesis that the brain is sensitive to the potentiality waves in the cosmic field, as ordinary measuring instruments in physics are sensitive to potentiality waves at the quantum level, so that the cosmic field can communicate with the human brain. The third proposal assumes that the communication with the cosmic field can translate into moral ideas and actions. Even though the three proposals underlying the thought experiment are highly speculative, they lead to definite implications that make sense in their own right and can be applied in a useful way. From the order of reality some simple rules of conduct follow that are identical with traditional moral rules but have the character of rules of well-ness, leading to new aspects of Aristotle's concept of eudaimonia and Kant's concept of the highest good. In analogy with the structure of physical reality, where all empirical phenomena are actualizations of nonempirical forms, it is suggested that the structure of morality, too, is that of a tacit, nonempirical form that actualizes in explicit principles and moral acts through our consciousness. The tacit form is thought to exist in the realm of cosmic potentiality, together with all the other forms that the empirical world actualizes. It can appear spontaneously in our consciousness when needed, offering its guidance to our judgment and free will. Because it does not appear in the form of commandments accompanied by threats, the actions of the tacit moral form define a higher level of morality, similar to that offered by some aspects of the Christian teaching, where one acts not out of fear but on the desire to do things right. (shrink)

Quantum frameworks for modeling competitive ecological systems and self-organizing structures have been investigated under multiple perspectives yielded by quantum mechanics. These comprise the description of the phase-space prey–predator competition dynamics in the framework of the Weyl–Wigner quantum mechanics. In this case, from the classical dynamics described by the Lotka–Volterra (LV) Hamiltonian, quantum states convoluted by statistical gaussian ensembles can be analytically evaluated. Quantum modifications on the patterns of equilibrium and stability of the prey–predator dynamics can (...) then be identified. These include quantum distortions over the equilibrium point drivers of the LV dynamics which are quantified through the Wigner current fluxes obtained from an onset Hamiltonian background. In addition, for gaussian ensembles highly localized around the equilibrium point, stability properties are shown to be affected by emergent topological quantum domains which, in some cases, could lead either to extinction and revival scenarios or to the perpetual coexistence of both prey and predator agents identified as quantum observables in microscopic systems. Conclusively, quantum and gaussian statistical driving parameters are shown to affect the stability criteria and the time evolution pattern for such microbiological-like communities. (shrink)

As quantum technologies (QT) advance, their potential impact on and relation with society has been developing into an important issue for exploration. In this paper, we investigate the topic of democratization in the context of QT, particularly quantum computing. The paper contains three main sections. First, we briefly introduce different theories of democracy (participatory, representative, and deliberative) and how the concept of democratization can be formulated with respect to whether democracy is taken as an intrinsic or instrumental value. (...) Second, we give an overview of how the concept of democratization is used in the QT field. Democratization is mainly adopted by companies working on quantum computing and used in a very narrow understanding of the concept. Third, we explore various narratives and counter-narratives concerning democratization in QT. Finally, we explore the general efforts of democratization in QT such as different forms of access, formation of grassroot communities and special interest groups, the emerging culture of manifesto writing, and how these can be located within the different theories of democracy. In conclusion, we argue that although the ongoing efforts in the democratization of QT are necessary steps towards the democratization of this set of emerging technologies, they should not be accepted as sufficient to argue that QT is a democratized field. We argue that more reflexivity and responsiveness regarding the narratives and actions adopted by the actors in the QT field and making the underlying assumptions of ongoing efforts on democratization of QT explicit, can result in a better technology for society. (shrink)

Quantum field theory is generally accepted by the modern scientific community as the most accurate paradigm for understanding the mystery of reality. This theory revolutionizes what we know as ’matter’ and how material things are connected. But is also confirms an ancient philosophical and ethical truth: the unfathomable mystery of being. Quantum field theory demonstrates that beings be in such a manner that their composite reality evades human cognition. Quantum field theory forces a rethinking of what we (...) mean by ’world’, ’beings’, ’existence’, and ’God’, and our assumptions about order, God, responsibility and systems of ethics. (shrink)

ABSTRACTThis contribution argues that Bohr's notion of complementarity can be traced back to the Laozi which he would have read. In Chinese philosophy, polar contrasts such as yin and yang are not regarded as mutually exclusive; they are co-present, existing as a harmonious Whole. Such a conception of metaphysics and logic stood Bohr in good stead for characterising quantum phenomena which are at once both wave and particle. His notion of complementarity bears witness to the possibility of communication (...) and understanding between two different philosophical approaches and scientific traditions—this account adds to Lloyd's concept of semantic stretch. (shrink)

Some physicists seem to believe that quantum information theory requires a new concept of information (Jozsa, 1998, Quantum information and its properties. In: Hoi-Kwong Lo, S. Popescu, T. Spiller (Eds.), Introduction to Quantum Computation and Information, World Scientific, Singapore, (pp. 49-75); Deutsch & Hayden, 1999, Information flow in entangled quantum subsystems, preprint quant-ph/9906007). I will argue that no new concept is necessary. Shannon's concept of information is sufficient for quantum information theory. Properties that are cited (...) to contrast quantum information and classical information (i.e., Shannon information) actually point to differences in our ability to manipulate, access, and transfer information depending on whether quantum systems, opposed to classical systems, are used in a communication system. I also demonstrate that conceptually puzzling phenomena in quantum information theory, such as dense coding, teleportation, and Schumacher coding, all of which are cited as evidence that a new concept of information is required, do not have to be regarded as such. (shrink)

This paper develops a hermeneutic technology assessment of quantum technologies. It offers a “vision assessment” of quantum technologies that can eventually lead to socio-ethical analysis. Section 2 describes this methodological approach and in particular the concept of the hermeneutic circle applied to technology. Section 3 gives a generic overview of quantum technologies and their impacts. Sections 4 and 5 apply the hermeneutic technology assessment approach to the study of quantum technologies. Section 5 proposes distinguishing three levels (...) in the analysis of the creation and communication of social meanings to quantum technologies: (a) fictions, (b) popularization, and (c) scientific journalism. Section 6 analyzes the results and defines some lines of action to increase social acceptance and trust in quantum technologies. The aim of this paper is to contribute to the debate on quantum technologies by enhancing the reflection on them and their potential, as well as illustrating the complexity of technological innovation and the need to shape it. (shrink)

In this work we will deal only with the concept of information in the communicational context, in which information is primarily something that has to be transmitted for communication purposes. The aim of the paper is to consider some arguments traditionally put forward to support the idea that quantum information is qualitatively different than classical information. On the basis of the analysis of those arguments, we will conclude that there are no reasons to admit the existence of (...) class='Hi'>quantum information as qualitatively different from classical information: there is only one kind of information, physically neutral, which can be encoded by means of classical or of quantum states. (shrink)

The conference Quantum Africa 2010 addressed recent advances, both theoretical and experimental, in the rapidly progressing field of quantum technologies. In particular progress in the foundations of quantum cryptography, quantum computing as well as quantum metrology was reported.

Alternate View Column AV-48 Keywords: nonlinear quantum mechanics FTL communication other universes Everett Wheeler Published in the October-1991 issue of Analog Science Fiction & Fact Magazine ; This column was written and submitted 3/10/91 and is copyrighted ©1991 by John G. Cramer. All rights reserved. No part may be reproduced in any form without the explicit permission of the author.

Alternate View Column AV-62 Keywords: quantum nonlocality entangled states recreation communication Published in the December-1993 issue of Analog Science Fiction & Fact Magazine ; This column was written and submitted 5/17/93 and is copyrighted ©1993 by John G. Cramer. All rights reserved. No part may be reproduced in any form without the explicit permission of the author.

Some physicists seem to believe that quantum information theory requires a new concept of information , Introduction to Quantum Computation and Information, World Scientific, Singapore, ; Deutsch & Hayden, 1999, Information flow in entangled quantum subsystems, preprint quant-ph/9906007). I will argue that no new concept is necessary. Shannon's concept of information is sufficient for quantum information theory. Properties that are cited to contrast quantum information and classical information actually point to differences in our ability to (...) manipulate, access, and transfer information depending on whether quantum systems, opposed to classical systems, are used in a communication system. I also demonstrate that conceptually puzzling phenomena in quantum information theory, such as dense coding, teleportation, and Schumacher coding, all of which are cited as evidence that a new concept of information is required, do not have to be regarded as such. (shrink)

Making Sense of Inner Sense 'Terra cognita' is terra incognita. It is difficult to find someone not taken abackand fascinated by the incomprehensible but indisputable fact: there are material systems which are aware of themselves. Consciousness is self-cognizing code. During homo sapiens's relentness and often frustrated search for self-understanding various theories of consciousness have been and continue to be proposed. However, it remains unclear whether and at what level the problems of consciousness and intelligent thought can be resolved. Science's greatest (...) challenge is to answer the fundamental question: what precisely does a cognitive state amount to in physical terms? Albert Einstein insisted that the fundamental ideas of science are essentially simple and can be expressed in a language comprehensible to everyone. When one thinks about the complexities which present themselves in modern physics and even more so in the physics of life, one may wonder whether Einstein really meant what he said. Are we to consider the fundamental problem of the mind, whose understanding seems to lie outside the limits of the mind, to be essentially simple too? Knowledge is neither automatic nor universally deductive. Great new ideas are typically counterintuitive and outrageous, and connecting them by simple logical steps to existing knowledge is often a hard undertaking. The notion of a tensor was needed to provide the general theory of relativity; the notion of entropy had to be developed before we could get full insight into the laws of thermodynamics; the notice of information bit is crucial for communication theory, just as the concept of a Turing machine is instrumental in the deep understanding of a computer. To understand something, consciousness must reach an adequate intellectual level, even more so in order to understand itself. Reality is full of unending mysteries, the true explanation of which requires very technical knowledge, often involving notions not given directly to intuition. Even though the entire content and the results of this study are contained in the eight pages of the mathematical abstract, it would be unrealistic and impractical to suggest that anyone can gain full insight into the theory that presented here after just reading abstract. In our quest for knowledge we are exploring the remotest areas of the macrocosm and probing the invisible particles of the microcosm, from tiny neutrinos and strange quarks to black holes and the Big Bang. But the greatest mystery is very close to home: the greatest mystery is human consciousness. The question before us is whether the logical brain has evolved to a conceptual level where it is able to understand itself. (shrink)