scholarly journals Interatomic interaction of two ground-state atoms in vacuum: Contributions of vacuum fluctuations and radiation reaction

2021 ◽  
Vol 103 (1) ◽  
Author(s):  
Wenting Zhou ◽  
Shijing Cheng ◽  
Hongwei Yu
Keyword(s):  
Ground State ◽  
Interatomic Interaction ◽  
Radiation Reaction ◽  
Vacuum Fluctuations

scholarly journals Fast Vacuum Fluctuations and the Emergence of Quantum Mechanics

2021 ◽  
Vol 51 (3) ◽  
Author(s):  
Gerard ’t Hooft
Keyword(s):  
Quantum Mechanics ◽  
Ground State ◽  
Quantum Interference ◽  
Direct Detection ◽  
Energy Levels ◽  
Vacuum Fluctuations ◽  
Heavy Particles ◽  
Evolving Systems ◽  
Gedanken Experiment ◽  
Classical Computer

AbstractFast moving classical variables can generate quantum mechanical behavior. We demonstrate how this can happen in a model. The key point is that in classically (ontologically) evolving systems one can still define a conserved quantum energy. For the fast variables, the energy levels are far separated, such that one may assume these variables to stay in their ground state. This forces them to be entangled, so that, consequently, the slow variables are entangled as well. The fast variables could be the vacuum fluctuations caused by unknown super heavy particles. The emerging quantum effects in the light particles are expressed by a Hamiltonian that can have almost any form. The entire system is ontological, and yet allows one to generate interference effects in computer models. This seemed to lead to an inexplicable paradox, which is now resolved: exactly what happens in our models if we run a quantum interference experiment in a classical computer is explained. The restriction that very fast variables stay predominantly in their ground state appears to be due to smearing of the physical states in the time direction, preventing their direct detection. Discussions are added of the emergence of quantum mechanics, and the ontology of an EPR/Bell Gedanken experiment.

EFFECTS OF A BOUNDARY ON SPONTANEOUS EXCITATION OF AN ACCELERATED MULTILEVEL ATOM COUPLED WITH THE DERIVATIVE OF SCALAR FIELDS

2007 ◽  
Vol 22 (20) ◽  
pp. 3447-3461
Author(s):  
YUNFENG ZHU ◽  
HONGWEI YU
Keyword(s):  
Radiation Reaction ◽  
Scalar Fields ◽  
Normal Direction ◽  
Coupling Scheme ◽  
Quantum Fields ◽  
Vacuum Fluctuations ◽  
Direction Parallel ◽  
Excitation Rate ◽  
Derivative Coupling ◽  
Multilevel Atom

The presence of boundaries modifies the modes of quantum fields, which may in turn modifies the spontaneous excitation rate of accelerated atoms in interaction with these fields. In this paper, we study the effect of the presence of a reflecting boundary on the spontaneous excitation of a uniformly accelerated polarized multilevel atom interacting with quantum scalar fields in a dipole-derivative coupling scheme. We separately calculate the contributions of modified vacuum fluctuations and the radiation reaction to the spontaneous excitation rate of the atom. Our results show that the presence of the boundary modulates the excitation rate and makes it a function of the atom's distance from the boundary. When the atom is placed closer and closer to the boundary, the influence of the boundary becomes more and more drastic, with the contribution of the atom's polarization in the direction parallel to the boundary to the spontaneous excitation rate dramatically suppressed while that in the normal direction greatly enhanced.

scholarly journals Vacuum fluctuations and radiation reaction : identification of their respective contributions

1982 ◽  
Vol 43 (11) ◽  
pp. 1617-1638 ◽  
Author(s):  
J. Dalibard ◽  
J. Dupont-Roc ◽  
C. Cohen-Tannoudji
Keyword(s):  
Radiation Reaction ◽  
Vacuum Fluctuations

scholarly journals Atom-Field Interaction: From Vacuum Fluctuations to Quantum Radiation and Quantum Dissipation or Radiation Reaction

Physics ◽  
2019 ◽  
Vol 1 (3) ◽  
pp. 430-444 ◽  
Author(s):  
Jen-Tsung Hsiang ◽  
B. L. Hu
Keyword(s):  
Degrees Of Freedom ◽  
Mutual Influence ◽  
Equations Of Motion ◽  
Free Field ◽  
Radiation Reaction ◽  
Linear Response Theory ◽  
Quantum Field ◽  
Quantum Dissipation ◽  
Vacuum Fluctuations ◽  
Quantum Radiation

In this paper, we dwell on three issues: (1) revisit the relation between vacuum fluctuations and radiation reaction in atom-field interactions, an old issue that began in the 1970s and settled in the 1990s with its resolution recorded in monographs; (2) the fluctuation–dissipation relation (FDR) of the system, pointing out the differences between the conventional form in linear response theory (LRT) assuming ultra-weak coupling between the system and the bath, and the FDR in an equilibrated final state, relaxed from the nonequilibrium evolution of an open quantum system; (3) quantum radiation from an atom interacting with a quantum field: We begin with vacuum fluctuations in the field acting on the internal degrees of freedom (idf) of an atom, adding to its dynamics a stochastic component which engenders quantum radiation whose backreaction causes quantum dissipation in the idf of the atom. We show explicitly how different terms representing these processes appear in the equations of motion. Then, using the example of a stationary atom, we show how the absence of radiation in this simple cases is a result of complex cancellations, at a far away observation point, of the interference between emitted radiation from the atom and the local fluctuations in the free field. In so doing we point out in Issue 1 that the entity which enters into the duality relation with vacuum fluctuations is not radiation reaction, which can exist as a classical entity, but quantum dissipation. Finally, regarding issue 2, we point out for systems with many atoms, the co-existence of a set of correlation-propagation relations (CPRs) describing how the correlations between the atoms are related to the propagation of their (retarded non-Markovian) mutual influence manifesting in the quantum field. The CPR is absolutely crucial in keeping the balance of energy flows between the constituents of the system, and between the system and its environment. Without the consideration of this additional relation in tether with the FDR, dynamical self-consistency cannot be sustained. A combination of these two sets of relations forms a generalized matrix FDR relation that captures the physical essence of the interaction between an atom and a quantum field at arbitrary coupling strength.

scholarly journals The Role of Vacuum Fluctuations and Symmetry in the Hydrogen Atom in Quantum Mechanics and Stochastic Electrodynamics

Atoms ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 39
Author(s):  
G. Maclay
Keyword(s):  
Electromagnetic Field ◽  
Hydrogen Atom ◽  
Casimir Effect ◽  
Classical Mechanics ◽  
Zero Point ◽  
Radiation Reaction ◽  
Quantum Mechanical ◽  
Vacuum Fluctuations ◽  
Stochastic Electrodynamics

Stochastic Electrodynamics (SED) has had success modeling black body radiation, the harmonic oscillator, the Casimir effect, van der Waals forces, diamagnetism, and uniform acceleration of electrodynamic systems using the stochastic zero-point fluctuations of the electromagnetic field with classical mechanics. However the hydrogen atom, with its 1/r potential remains a critical challenge. Numerical calculations have shown that the SED field prevents the electron orbit from collapsing into the proton, but, eventually the atom becames ionized. We look at the issues of the H atom and SED from the perspective of symmetry of the quantum mechanical Hamiltonian, used to obtain the quantum mechanical results, and the Abraham-Lorentz equation, which is a force equation that includes the effects of radiation reaction, and is used to obtain the SED simulations. We contrast the physical computed effects of the quantized electromagnetic vacuum fluctuations with the role of the real stochastic electromagnetic field.

Atomic ground state energy in multiply connected universes

1980 ◽  
Vol 372 (1749) ◽  
pp. 297-306 ◽  
Keyword(s):  
Hydrogen Atom ◽  
Minkowski Space ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Energy Shift ◽  
Vacuum Fluctuations ◽  
Static Polarizability ◽  
Multiply Connected ◽  
Atomic Ground State

We consider a hydrogen atom interacting with electromagnetic vacuum fluctuations in a variety of multiply connected universes, and calculate, to order e 2 , the shift in energy of its ground state from the value it would take in Minkowski space. The classical dipole self-interaction is also included and, for investigation, we choose universes with underlying manifolds R 1 ⊗ T 3 , R 1 ⊗ B 1 and R 1 ⊗ G 2 upon each of which we impose a flat metric. In all cases, we find the energy shift to be proportional to the atom’s static polarizability.

Radiation reaction and vacuum fluctuations in spontaneous emission

1975 ◽  
Vol 11 (3) ◽  
pp. 814-824 ◽  
Author(s):  
Peter W. Milonni ◽  
Wallace Arden Smith
Keyword(s):  
Spontaneous Emission ◽  
Radiation Reaction ◽  
Vacuum Fluctuations

scholarly journals A MICROSCOPIC LOOK AT LIQUID HELIUM: THE 3He IMPURITY CASE

2001 ◽  
Vol 15 (10n11) ◽  
pp. 1575-1590
Author(s):  
A. POLLS ◽  
A. FABROCINI
Keyword(s):  
Monte Carlo ◽  
Liquid Helium ◽  
Basis Function ◽  
Ground State ◽  
Interatomic Interaction ◽  
Many Body ◽  
Excitation Energies ◽  
Momentum Range ◽  
Particle Correlation ◽  
Correlation Operator

The description of the properties of liquid Helium is a challenge for any microscopic many-body theory. In this context, we study the ground state and the excitation spectrum of one 3 He impurity in liquid 4 He at T=0 with the aim of illustrating the power of the correlated basis function formalism in describing heavily correlated systems. The strong interatomic interaction and the large density require the theory to be pushed to a high degree of sophistication. A many-body correlation operator containing explicit two- and three-particle correlation functions is needed to obtain a realistic ground state wave function, whereas a perturbative expansion including up to two phonon correlated states must be enforced to study the impurity excitation energies. The theory describes accurately the experimental spectrum along all the available momentum range. As empirically shown by the experiments, a marked deviation from the quadratic Landau-Pomeranchuck behavior is found and the momentum dependent effective mass of the impurity increases of ~50% at q~1.7 Å-1 with respect to its q=0 value. Although the main emphasis is given to the correlated basis function theory, we present also comparisons with other methods, as diffusion Monte Carlo, variational Monte Carlo with shadow wave functions and time dependent correlations.

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