Einstein-Hopf drag, Doppler shift of thermal radiation and blackbody drag: Three perspectives on quantum friction

Open Physics ◽  
2012 ◽  
Vol 10 (4) ◽  
Author(s):  
Grzegorz Łach ◽  
Maarten DeKieviet ◽  
Ulrich Jentschura
Keyword(s):  
Electromagnetic Field ◽  
Thermal Radiation ◽  
Drag Force ◽  
Doppler Shift ◽  
Thermal Fluctuations ◽  
Harmonic Oscillators ◽  
Field Energy ◽  
Simple Explanation ◽  
Quantum Friction ◽  
Atomic Polarizability

AbstractThe thermal friction force acting on an atom moving relative to a thermal photon bath has recently been calculated on the basis of the fluctuation-dissipation theorem. The thermal fluctuations of the electromagnetic field give rise to a drag force on an atom provided one allows for dissipation of the field energy via spontaneous emission. The drag force exists if the atomic polarizability has a nonvanishing imaginary part. Here, we explore alternative derivations. The damping of the motion of a simple harmonic oscillator is described by radiative reaction theory (result of Einstein and Hopf), taking into account the known stochastic fluctuations of the electromagnetic field. Describing the excitations of the atom as an ensemble of damped harmonic oscillators, we identify the previously found expressions as generalizations of the Einstein-Hopf result. In addition, we present a simple explanation for blackbody friction in terms of a Doppler shift of the thermal radiation in the inertial frame of the moving atom: The atom absorbs blue-shifted photons from the front and radiates off energy in all directions, thereby losing energy. The original plus the two alternative derivations provide for additional confirmation of an intriguing quantum friction effect, and leave no doubt regarding its existence.

scholarly journals Velocity effect on the stimulated transition process of a multilevel atom in a thermal bath

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Huabing Cai
Keyword(s):  
Electromagnetic Field ◽  
Perturbation Theory ◽  
Transition Process ◽  
Stimulated Emission ◽  
Atomic Transition ◽  
Thermal Bath ◽  
Transition Rates ◽  
Atomic Polarizability ◽  
Velocity Effect ◽  
Multilevel Atom

AbstractThis paper investigates the stimulated transition process of a uniformly moving atom in interaction with a thermal bath of the quantum electromagnetic field. Using the perturbation theory, the atomic stimulated emission and absorption rates are calculated. The results indicate that the atomic transition rates depend crucially on the atomic velocity, the temperature of the thermal bath, and the atomic polarizability. As these factors change, the atomic stimulated transition processes can be enhanced or weakened at different degrees. In particular, slowly moving atoms in the thermal bath with high temperature ($$T\gg \omega _{0}$$ T ≫ ω 0 ) perceive a smaller effective temperature $$T \big ( 1-\frac{1}{10} v^{2} \big )$$ T ( 1 - 1 10 v 2 ) for the polarizability perpendicular to the atomic velocity or $$T \big ( 1-\frac{3}{10} v^{2} \big )$$ T ( 1 - 3 10 v 2 ) for the polarizability parallel to the atomic velocity. However, ultra-relativistic atoms perceive no influence of the background thermal bath. In turn, in terms of the atomic transition rates, this paper explores and examines the relativity of temperature of the quantum electromagnetic field.

scholarly journals Foundations of the new field theory

1934 ◽  
Vol 144 (852) ◽  
pp. 425-451 ◽  
Keyword(s):  
Field Theory ◽  
Electromagnetic Field ◽  
Field Energy ◽  
Physical Entity ◽  
Electromagnetic Mass

The relation of matter and the electromagnetic field can be interpreted from two opposite standpoints:— The first which may be called the unitarian standpoint assumes only one physical entity, the electromagnetic field. The particles of matter are considered as singularities of the field and mass is a derived notion to be expressed by field energy (electromagnetic mass).

Thermal effect in the resonance fluorescence of a two-level system

1991 ◽  
Vol 69 (11) ◽  
pp. 1367-1372
Author(s):  
C. H. A. Fonseca ◽  
L. A. Amarante Ribeiro
Keyword(s):  
Equations Of Motion ◽  
Normal Modes ◽  
Thermal Fluctuations ◽  
Harmonic Oscillators ◽  
Thermal Bath ◽  
Resonance Fluorescence ◽  
Level System ◽  
Near Resonance ◽  
Intensity Correlation Function ◽  
Heisenberg Equations

The damped two-level system, driven by a strong incident classical field near resonance frequency is subjected to the effect of thermal fluctuations. To simulate the thermal bath we introduce a large system of harmonic oscillators that represents the normal modes of the thermal radiation field. From the Heisenberg equations of motion we calculate the power spectrum of the scattered field and the intensity correlation function. The results show that the presence of the bath dramatically modifies the light scattered by the two-level system when compared with the case without a thermal bath.

scholarly journals The relativistic foundations of synchrotron radiation

2017 ◽  
Vol 24 (4) ◽  
pp. 898-901 ◽  
Author(s):  
Giorgio Margaritondo ◽  
Johann Rafelski
Keyword(s):  
Electromagnetic Field ◽  
Synchrotron Radiation ◽  
Special Relativity ◽  
Reference Frame ◽  
Lorentz Transformation ◽  
Doppler Shift ◽  
Time Dilation ◽  
Common Belief ◽  
Research Discipline ◽  
Radiation Properties

Special relativity (SR) determines the properties of synchrotron radiation, but the corresponding mechanisms are frequently misunderstood. Time dilation is often invoked among the causes, whereas its role would violate the principles of SR. Here it is shown that the correct explanation of the synchrotron radiation properties is provided by a combination of the Doppler shift, not dependent on time dilation effects, contrary to a common belief, and of the Lorentz transformation into the particle reference frame of the electromagnetic field of the emission-inducing device, also with no contribution from time dilation. Concluding, the reader is reminded that much, if not all, of our argument has been available since the inception of SR, a research discipline of its own standing.

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