In this paper we review the discussion about quantum jumps. We sketch the historical background before we present the recent revival of this problem originating in the field of atomic investigations. We present both the theoretical methods and their motivations, the relevance to experiments and an attempt at a preliminary discussion of the role of these developments in our fundamental understanding of quantum physics.
In this paper we review the discussion about quantum jumps. We sketch the historical background before we present the recent revival of this problem originating in the field of atomic investigations. We present both the theoretical methods and their motivations, the relevance to experiments and an attempt at a preliminary discussion of the role of these developments in our fundamental understanding of quantum physics.
The foundations of quantum mechanics have been a subject of intense investigation and debate since the theory's inception. Recent developments in quantum technologies and theoretical frameworks have shed new light on foundational issues and raised intriguing questions about the nature of reality at the quantum level. recent advancements in our understanding of the foundational principles of quantum mechanics and discuss unresolved questions that continue to challenge our conceptual framework. Topics of interest include the measurement problem, quantum entanglement, the role of contextuality and nonlocality, interpretations of quantum theory, and the quest for a unified theory of quantum gravity. findings and ongoing debates in the field, we aim to provide a comprehensive overview of the current state of research in the foundations of quantum mechanics and stimulate further discussion and inquiry into these fundamental questions.
Introduction The quantum theory of atoms and molecules had its origin in the famous 1913 paper of Bohr [186] in which he suggested that the interaction of radiation and atoms occurred with the transition of an atom from one stationary internal state to another, accompanied by the emission or absorption of radiation of a frequency determined by the energy difference between these states. These transitions came to be known as ‘quantum jumps’. Since all experiments until the late 1970s used to be carried out with large ensembles of atoms and molecules, these jumps were masked and could not be directly observed; they were only inferred from spectroscopic data. In fact, with the advent of quantum mechanics they eventually came to be regarded as artefacts of Bohr's simple-minded semi-classical model. But with the availability of coherent light sources and single ions prepared in ion traps [187], [188], and optically cooled [189], [190], the issue has been reopened with the experimental demonstration of quantum jumps in single ions [191], [192], [193]. These experiments have also opened up the contentious issue of wave function collapse or reduction on measurement, as they can be regarded as making collapse visible on the oscilloscope screen [191]. Evidence of the discrete nature of quantum transitions in a single quantum system had been accumulating from the observation of photon anti-bunching in single-atom resonance fluorescence [194], the tunneling of single electrons in metal–oxide-–semiconductor junctions [195] and spin-flips of individual electrons in a Penning trap [196].
Abstract This review article presents historical developments and recent advances in our understanding on the three-body forces and Efimov physics, from an interdisciplinary viewpoint encompassing nuclear physics and cold atoms. Theoretical attempts to elucidate the three-body force with the chiral effective field theory are explained, followed by an overview of experiments aimed at observing signatures of the nuclear three-body force. Some recent experimental and theoretical works in the field of cold atoms devoted to measuring and engineering three-body forces among atoms are also presented. As a phenomenon arising from the three-body effect, Efimov physics in both cold atoms and nuclear systems is reviewed.
Since 1986 a vast body of experimental evidence has been accumulated of direct observation of quantum jumps in many physical systems. We can therefore assume that quantum jumps are genuine physical phenomena. On the other hand, substantial identity of "quantum jumps" and "collapses" induced by measurements can be admitted, both being represented by self-conjugate projection operators related to specific non-Hamiltonian aspects of micro-interactions. On this basis a model of quantum jump involving a single particle is discussed, and some consequences concerning hadronic physics (Hagedorn temperature, Regge trajectories) and quantum gravity are briefly sketched.
This paper considers the recent description of quantum time evolution in terms of a sequence of discrete quantum jumps. The historical development of continuous time evolution versus sudden jumps is reviewed. A time irreversible master equation is derived heuristically by considering random interruptions of the Schrodinger time development by external interventions characterized by a broad spectrum. The concrete examples we have in mind are atomic collisions and photon counting events. The formulation chosen allows a more general approach to the problem than conventional perturbative treatments. The conserved quantities are considered, and the effects of a dynamical superselection rule is discussed. It is pointed out, that these often break the time reversal symmetry and constitute a counting process which can be regarded as a measurement. Under certain conditions, the intervening process can be decomposed into simple jump processes that allow a simulation in terms of a quantum stochastic process. The significance of the results, their historical origins and the relations to contemporary investigations are all being discussed.
Quantum information technology mainly includes quantum communication, quantum radar, quantum computer these three aspects, in recent years, rapid development, many countries invested heavily in development. The awarding of the Nobel Prize in Physics in 2022 to three scientists for their work in quantum informatics has further stimulated people's interest in quantum theory, which has been studied and discussed. This paper not only reviews the historical situation, but also thinks and innovates in theory. The main contents of this paper are as follows: It is pointed out that there are fundamental contradictions between relativity and quantum mechanics; The wave function, quantum statistics and uncertainty principle are discussed in detail. The hidden variable theory is reviewed and the Bell inequality is discussed. The Aspect two-photon experiment was analyzed. The rationality of Bohm experiment scheme is discussed. The development of Bell type experiment is discussed. It is pointed out that the entangled state is not acting at a distance but propagating faster than the speed of light. Reviews the Copenhagen interpretation of quantum mechanics; Quantum communication and Wootters theorem are discussed. etc. This paper holds that quantum mechanics has been finalized from 1926 to 1928, and its basic content has not changed much. But for some of the accusations, it is necessary to answer them theoretically. For example, we believe that the Copenhagen interpretation fundamentally changes our understanding of nature and marks a profound revolution in physics. And no other theory has since emerged that has such a profound understanding and wide application of microscopic phenomena as this interpretation. Another example is Bohm's two-particle correlation spin scheme in quantum entanglement experiments, which has been proved to be effective in a series of experiments, which is an important contribution in Bohm's life. This paper holds that the so-called quantum field theory is a failure, and the original quantum mechanics should still be advocated today. Current theoretical research should pay great attention to quantum entangled states, because its nature is still unclear. Understanding this "first mystery of the physical world" not only has scientific significance, but also has great philosophical significance for understanding the universe.