Quantum measurement problem is a long-standing problem at the heart of the foundations of modern physics and nascent technology, such as quantum technology. The last forty years brought a renowned interest in this problem with an emphasis on the new foundations of quantum theory and unpredicted formulation of some new quantum disciplines, such as the open quantum systems theory and the quantum information and computation science. A state of the art of the problem of measurement is shortly presented, including a brief historical view, with a review of the authors' original contributions.
Quantum measurement problem is a long-standing problem at the heart of the foundations of modern physics and nascent technology, such as quantum technology. The last forty years brought a renowned interest in this problem with an emphasis on the new foundations of quantum theory and unpredicted formulation of some new quantum disciplines, such as the open quantum systems theory and the quantum information and computation science. A state of the art of the problem of measurement is shortly presented, including a brief historical view, with a review of the authors' original contributions.
Quantum Information Theory (QIT) has emerged as one of the most influential fields in modern science, combining the principles of quantum mechanics with classical information theory. It forms the theoretical foundation of advanced technologies such as quantum computing, quantum communication, and quantum cryptography. Despite remarkable progress in these areas, the measurement problem remains a fundamental conceptual and practical challenge. Measurement in quantum mechanics plays a dual role: it enables information extraction while simultaneously disturbing the quantum system. This paper presents a detailed study of the measurement problem within the framework of quantum information theory. It examines the role of measurement in quantum state evolution, the effects of entanglement and decoherence, and the impact on information processing tasks. The paper also discusses existing theoretical approaches and highlights the importance of resolving measurement-related issues for the future development of quantum technologies.
We reconsider some important foundational problems of quantum mechanics. After reviewing the measurement problem and discussing its unavoidability, we analyze some proposals to overcome it. This analysis leads us to reconsider the current debate on our best theory, i.e. quantum mechanics itself. We stress that, after the remarkable interest and the many efforts which have lead, in the last years of the past century, to a revival of the subject, and, more important, to new interesting results, we are now witnessing a re-emergence of the vague and unprofessional positions which have characterized the debate in the second quarter of the XXth century. In particular we consider as extremely serious the fact that a completely mistaken position concerning the real meaning of Bell's theorem seems to have been taken by many scientists in the field.
Left on its own, a quantum state evolves deterministically under the Schrödinger equation, forming superpositions. Upon measurement, however, a stochastic process governed by the Born rule collapses it to a single outcome. This dual evolution of quantum states – the core of the Measurement Problem – has puzzled physicists and philosophers for nearly a century. Yet, amid the cacophony of competing interpretations, the problem today is not as impenetrable as it once seemed. This paper reviews the current status of the Measurement Problem, distinguishing between what is well understood and what remains unresolved. We examine key theoretical approaches, including decoherence, many-worlds interpretation, objective collapse theories, hidden-variable theories, dualistic approaches, deterministic models, and epistemic interpretations. To make these discussions accessible to a broader audience, we also reference curated online resources that provide high-quality introductions to central concepts.
Quantum science underpins many of the most significant advances in modern physics, chemistry, and information technology. Quantum physics provides the fundamental laws governing matter and energy at microscopic scales, quantum chemistry applies these principles to explain molecular structure, bonding, and reactivity, and quantum computing seeks to exploit quantum phenomena such as superposition and entanglement to enable new computational paradigms. Despite their long-standing theoretical foundations and experimental successes, all three domains remain surrounded by persistent misconceptions, often amplified by abstract formalisms, popular science narratives, and rapid technological developments. This contemporary review critically examines the established facts and common myths associated with quantum physics, quantum chemistry, and quantum computing. Emphasis is placed on experimentally verified principles, computational feasibility, and realistic assessments of current capabilities. Recent advances reported between 2020 and 2025 are reviewed to highlight genuine progress in areas such as quantum simulations, molecular modeling, and noisy intermediate-scale quantum (NISQ) devices, while also addressing their practical limitations. By distinguishing validated achievements from speculative claims, this review provides a balanced, evidence-based perspective on modern quantum science. The article aims to clarify enduring misconceptions, promote conceptual clarity across disciplines, and outline realistic future directions for research and applications in quantum technologies.
This special issue is situated at the interface between Logic and the Foundations of Physics.This interface, though not as active as the logical foundations of mathematics, has long existed-with highlights such as "quantum logic", or studies of the general logical structure of physical theories.In recent years, more themes have come to the fore, and we may be witnessing a revival.The papers presented here emanate from a symposium held at the University of Utrecht in January 2008 with the aim of charting established as well as new connections between the two fields.One of the main questions discussed was whether and how modern techniques coming from logic, computer science and information theory might be combined with state-of-the-art insights in the philosophy of physics to gain a better understanding of the main foundational issues and open problems in modern physics.The success of this symposium has shown that there are several possible answers to this question.
Measurements play a specific role in quantum mechanics; only measurements allow us to catch a glimpse of the eluding physical reality. However, there is something deeply unsatisfactory with this specificity—a measurement is itself a physical process! Several varying modes of coping with this dilemma have been proposed and this article tries to describe how a now-century-long discussion has led to new insights about the transition from the quantum to the classical world. Starting from the pioneer’s view of the quantum measurement problem, it follows the development of formalisms, the interest from philosophers for its new aspects on reality and how different interpretations of quantum mechanics have tried to support our classically working brains in understanding quantum phenomena. Decoherence is a main topic and its role in measurement processes exemplified. The question of whether the quantum measurement problem is now solved is left open for the readers’ own judgment.