Modern quantum theory introduces quantum structures (decompositions into subsystems) as a new discourse that is not fully comparable with the classical-physics counterpart.To this end, socalled Entanglement Relativity appears as a corollary of the universally valid quantum mechanics that can provide for a deeper and more elaborate description of the composite quantum systems.In this paper we employ this new concept to describe the hydrogen atom.We offer a consistent picture of the hydrogen atom as an open quantum system that naturally answers the following important questions: 1) how do the so called "quantum jumps" in atomic excitation and de-excitation occur?and 2) why does the classically and seemingly artificial "center-of-mass + relative degrees of freedom" structure appear as the primarily operable form in most of the experimental reality of atoms?
Modern quantum theory introduces quantum structures (decompositions into subsystems) as a new discourse that is not fully comparable with the classical-physics counterpart.To this end, socalled Entanglement Relativity appears as a corollary of the universally valid quantum mechanics that can provide for a deeper and more elaborate description of the composite quantum systems.In this paper we employ this new concept to describe the hydrogen atom.We offer a consistent picture of the hydrogen atom as an open quantum system that naturally answers the following important questions: 1) how do the so called "quantum jumps" in atomic excitation and de-excitation occur?and 2) why does the classically and seemingly artificial "center-of-mass + relative degrees of freedom" structure appear as the primarily operable form in most of the experimental reality of atoms?
Hydrogen atom is studied as a quantum-classical hybrid system, where the proton is treated as a classical object while the electron is regarded as a quantum object. We use a well known mean-field approach to describe this hybrid hydrogen atom; the resulting dynamics for the electron and the proton is compared to their full quantum dynamics. The electron dynamics in the hybrid description is found to be only marginally different from its full quantum counterpart. The situation is very different for the proton: in the hybrid description, the proton behaves like a free particle; in the fully quantum description, the wave packet center of the proton orbits around the center of mass. Furthermore, we find that the failure to describe the proton dynamics properly can be regarded as a manifestation of the fact that there is no conservation of momentum in the mean-field hybrid approach. We expect that such a failure is a common feature for all existing approaches for quantum-classical hybrid systems of Born-Oppenheimer type.
We offer a systematic account of decomposition of quantum systems into parts. Different decompositions (structures) are mutually linked via the proper linear canonical transformations. Different kinds of structures, as well as their relations, are considered. Emphasis is placed on mutually global and irreducible structures. Is there a privileged structure of the closed system? Is there a preferred (bipartite) structure of an open system? Are there any practical advantages of certain alternative structures of the system? Is there a simple dynamical relation for a pair of structures? The [necessarily partial] answers are rather intriguing. Relativity of quantum correlations (that include entanglement as well as the "one-way" and "two-way" discord) is carefully presented. Emphasis is placed on the "parallel occurrence of decoherence" in the quantum Brownian motion. The environment-selected preferred structure of an open composite system is presented for a pair of harmonic oscillators (or the field modes). A limitation of the Nakajima-Zwanzig projection method appears as a consequence of quantum correlations relativity. Hence, describing dynamics of an alternate open-system is a delicate task. Certain interpretational issues, which include "quantum reference frames" issue, are discussed. Some recent experiments are also discussed. To this end, the option that "there are no particles" on the most fundamental physical level naturally follows. Certain open questions and prospects for further research are highlighted.
Abstract Although the classical electrodynamic theory meets with a considerable amount of success in the description of many atomic phenomena, it fails completely on certain fundamental points. It has long been thought that the way out of this difficulty lies in the fact that there is one basic assumption of the classical theory which is false, and that if this assumption were removed and replaced by something more general, the whole of atomic theory would follow quite naturally. Until quite recently, however, one has had no idea of what this assumption could be. A recent paper by Heisenberg* provides the clue to the solution of this question, and forms the basis of a new quantum theory. According to Heisenberg, if x and y are two functions of the co-ordinates and momenta of a dynamical system, then in general xy is not equal to yx. Instead of the commutative law of multiplication, the canonical variables qrpr (r = 1...u) of a system of u degrees of freedom satisfy the quantum conditions, which were given by the author in the form qrqs ― qsqr = 0 prps ― pspr = 0 qrps ― psqr = 0 qrpr ― prqr = ih (r ≠ s) } (1) where i is a root of — 1 and h is a real universal constant, equal to (2π)-1 times the usual Planck’s constant. These equations are just sufficient to enable one to calculate xy — yx when x and y are given functions of the p’s and q’s, and are therefore capable of replacing the classical commutative law of multiplication. They appear to be the simplest assumptions one could make which would give a workable theory.
We begin our study of atomic physics by relying on the phenomenological notions summarized in chapter 1 and by fully exploiting the quantum mechanical formalism outlined in chapter 2. A hierarchy of approximations will be introduced in the first instance to describe the hydrogen atom, which allows one to focus on the main features of its energy spectrum and quantum properties, including the key ‘atomic orbital’ concept. Next, these results will be extended to the more general case of hydrogenic atoms. The physical picture will be made more rigorous by introducing the magnetic interactions, included those linked to the intrinsic spin degree of freedom, leading to the full description of the fine and hyperfine structure of one-electron atoms. The effects of a static external magnetic or electric field will be eventually discussed by calculating the corresponding energy shifts and splittings of the energy levels.
The purpose of this work is to retrace the steps that were made by scientists of XX century, like Bohr, Schrodinger, Heisenberg, Pauli, Dirac, for the formulation of what today represents the modern quantum mechanics and that, within two decades, put in question the classical physics. In this context, the study of the electronic structure of hydrogen atom has been the main starting point for the formulation of the theory and, till now, remains the only real case for which the quantum equation of motion can be solved exactly. The results obtained by each theory will be discussed critically, highlighting limits and potentials that allowed the further development of the quantum theory.
We present the foundations of a new emerging interpretation of quantum theory bearing wide-range implications. Physical basis of the interpretation is non-questionable yet relatively new--it relies on the different structures (decompositions into parts, subsystems) of the quantum Universe. We compare the mutually irreducible structures of the Universe and recognize them as the different facets of the one and the same quantum Universe. Physical picture is interesting and non-reducible to the existing interpretations. As a particularly interesting topic in this context appears the 'free will' topic of current interest in the interpretation of quantum theory. To this end, we arrive at the following interesting observation. The freely chosen actions (e.g. quantum measurements) performed by a (conscious) agent that are still locally observable in the alternate Worlds could seem physically unexplainable ('non-physical', 'ghostly').