Quantum Electrodynamics of Charged Particles without Spin

1950 ◽  
Vol 80 (4) ◽  
pp. 666-687 ◽  
Author(s):  
F. Rohrlich
Keyword(s):  
Quantum Electrodynamics ◽  
Charged Particles

Generation and degree of entanglement in a relativistic formulation

2003 ◽  
Vol 3 (2) ◽  
pp. 115-120
Author(s):  
J. Pachos ◽  
E. Solano
Keyword(s):  
Quantum Electrodynamics ◽  
Charged Particles ◽  
Entangled States ◽  
Spin Interaction ◽  
Relativistic Invariance ◽  
Relativistic Formulation ◽  
Relativistic Version ◽  
Consistent Approach ◽  
Degree Of Entanglement ◽  
Dirac Spinors

The generation of entangled states and their degree of entanglement are studied in a relativistic formulation for the case of two interacting spin-1/2 charged particles. In the realm of quantum electrodynamics, we revisit the interaction that produces entanglement between the spin components of covariant Dirac spinors describing the two particles. In this way, we derive the relativistic version of the spin-spin interaction, widely used in the nonrelativistic regime. Following this consistent approach, the relativistic invariance of the generated entanglement is discussed.

Molecular quantum electrodynamics

1971 ◽  
Vol 321 (1547) ◽  
pp. 557-572 ◽  
Keyword(s):  
Electromagnetic Field ◽  
Quantum Electrodynamics ◽  
Unitary Transformation ◽  
Charged Particles ◽  
Gauge Condition ◽  
Binding Energies ◽  
Quantum Mechanical ◽  
Supplementary Condition ◽  
Molecular Systems ◽  
Hamiltonian Theory

A comparison is made of the conventional quantum mechanical hamiltonian for the interaction of molecular systems with the electromagnetic field and the alternative multipole formulation given recently (Atkins & Woolley 1970). The conventional hamiltonian is first derived by using Dirac’s generalized hamiltonian theory in which the Coulomb gauge condition is introduced as a supplementary condition. We analyse further the interpretation of the unitary transformation that connects the two hamiltonians in terms of the arbitrariness of the phase of the wavefunctions of charged particles in the presence of the electromagnetic field, and finally examine the problem of exhibiting explicitly the binding energies of the molecular systems.

scholarly journals On the Classical Theory of Equilibrium Between Matter and Radiation

1975 ◽  
Vol 28 (6) ◽  
pp. 715
Author(s):  
JJ Monaghan
Keyword(s):  
Electromagnetic Radiation ◽  
Quantum Electrodynamics ◽  
Mechanical Treatment ◽  
Charged Particles ◽  
Hamiltonian Formalism ◽  
Stimulated Emission ◽  
Quantum Mechanical ◽  
Quantum Mechanical Treatment ◽  
Simplifying Assumptions ◽  
Arbitrary Potential

The problem of establishing the Rayleigh-Jeans law for equilibrium electromagnetic radiation in a cavity is studied without making the customary simplifying assumptions. By using a Hamiltonian formalism analogous to that introduced by Fermi for quantum electrodynamics the analysis is simplified, general expressions for absorption and emission are obtained, and the correspondence with the quantum mechanical treatment is established. The model considered consists of a cavity which contains classical charged particles which move in an arbitrary potential while interacting with electromagnetic radiation. The work covers much the same ground as the fundamental but neglected work of McLaren, though the methods used are simpler and more direct. The applications are to those parts of radio astronomy where the wavelengths are sufficiently large to allow a classical description. In particular, Twiss's analysis of stimulated emission at radio wavelengths is incorporated in the analysis.

scholarly journals ON COHERENT AND INCOHERENT SCATTERING OF FAST CHARGED PARTICLES IN ULTRATHIN CRYSTALS

2020 ◽  
pp. 120-125
Author(s):  
N.F. Shul'ga ◽  
V.D. Koriukina
Keyword(s):  
Cross Section ◽  
Quantum Electrodynamics ◽  
Charged Particles ◽  
Incident Beam ◽  
Waller Factor ◽  
Incoherent Scattering ◽  
Scattering Cross Section ◽  
Scattering Cross ◽  
Debye Waller Factor ◽  
Crystallographic Axes

We consider the fast charged particles scattering in ultrathin crystals on the base of the Born approximation of quantum electrodynamics. The main attention is paid to the question of the scattering cross section splitting into coherent and incoherent components when one of the crystallographic axes and planes is oriented along the direction of particle motion. It is shown that both the coherent and the incoherent components of the scattering cross section considerably depend on the orientation of the crystallographic axes relatively to the incident beam. In particular, it was shown that when particles are scattered by the crystal planes of atoms, the incoherent scattering cross section does not contain the Debye-Waller factor.

Plasma scale length and quantum electrodynamics effects on particle acceleration at extreme laser plasmas

2021 ◽  
Vol 87 (6) ◽  
Author(s):  
Ozgur Culfa ◽  
Sinan Sagir
Keyword(s):  
Particle Acceleration ◽  
Quantum Electrodynamics ◽  
Charged Particles ◽  
Front Surface ◽  
Radiation Reaction ◽  
Maximum Energy ◽  
Particle In Cell ◽  
Qed Effects ◽  
Preformed Plasma ◽  
Scale Length

In this work, simulations of multipetawatt lasers at irradiances ${\sim }10^{23} \ \mathrm {W}\ \mathrm {cm}^{-2}$ , striking solid targets and implementing two-dimensional particle-in-cell code was used to study particle acceleration. Preformed plasma at the front surface of a solid target increases both the efficiency of particle acceleration and the reached maximum energy by the accelerated charged particles via nonlinear plasma processes. Here, we have investigated the preformed plasma scale length effects on particle acceleration in the presence and absence of nonlinear quantum electrodynamic (QED) effects, including quantum radiation reaction and multiphoton Breit–Wheeler pair production, which become important at irradiances ${\sim } 10^{23}\ \mathrm {W}\ \mathrm {cm}^{-2}$ . Our results show that QED effects help particles gain higher energies with the presence of preformed plasma. In the results for all cases, preplasma leads to more efficient laser absorption and produces more energetic charged particles, as expected. In the case where QED is included, however, physical mechanisms changed and generated secondary particles ( $\gamma$ -rays and positrons) reversing this trend. That is, the hot electrons cool down due to QED effects, while ions gain more energy due to different acceleration methods. It is found that more energetic $\gamma$ -rays and positrons are created with increasing scale length due to high laser conversion efficiency ( ${\sim }$ 24 % for $\gamma$ -rays and $\sim$ 4 % for positrons at $L = 7\ \mathrm {\mu }\textrm {m}$ scale length), which affects the ion and electron acceleration mechanisms. It is also observed that the QED effect reduces the collimation of angular distribution of accelerated ions because the dominant ion acceleration mechanism is changing when QED is involved in the process.

scholarly journals On the new field theory II─Quantum theory of field and charges

1937 ◽  
Vol 159 (898) ◽  
pp. 355-382 ◽  
Keyword(s):  
Field Theory ◽  
Electromagnetic Field ◽  
Quantum Theory ◽  
Quantum Electrodynamics ◽  
Present Author ◽  
Charged Particles ◽  
Quantum Mechanical ◽  
Mechanical Theory ◽  
Quantum Mechanical Theory ◽  
Quantum Treatment

The Purpose of this paper is to extend the quantum electrodynamics of the New Field theory to include the dynamics of charged particles. The work of Born and Infeld (Born 1934; Born and Infeld 1934 a , b , 1935) in which the theory has been developed, and of weiss (1936), has dealt with the quantum theory of the electromagnetic field alone, without allowing for the occurrence of point charges; this is inherent in their equation div D = 0. In a Previous paper (1936 a ), the present author has given a classical (i. e. non-quantum) treatment of the dynamics of point charges in the frame of the New Field theory. The analytical methods of that paper were chosen in such a way that they could be used in the generalization to a quantum-mechanical theory, and we shall here use them as the scaffolding for the present work. We shall therefore use the same notation as before. The more important symbols have the following meanings:

Quantum electrodynamics of spinless particles between conducting plates

1970 ◽  
Vol 320 (1541) ◽  
pp. 251-275 ◽  
Keyword(s):  
Electromagnetic Field ◽  
Hydrogen Atom ◽  
Free Electron ◽  
Quantum Electrodynamics ◽  
Lamb Shift ◽  
Charged Particles ◽  
Normal Modes ◽  
Single Plate ◽  
Quantized Electromagnetic Field ◽  
Limiting Case

The energy of any system containing charged particles arises partly from its coupling to the quantized electromagnetic field; it changes on inserting the system between conducting plates, because these alter the normal modes of the field relative to free space. We calculate to order e 2 such energy shifts for a free electron and for a hydrogen atom, neglecting spin, but allowing in full for electrostatic and retardation corrections as well as for changes in the Lamb shift proper. The potential between a particle and a single plate follows as a limiting case. An appendix details the distinction between classical and quantum effects.

scholarly journals On the Importance of Self-interaction in QCD

1991 ◽  
Vol 44 (3) ◽  
pp. 105 ◽  
Author(s):  
RT Cahill
Keyword(s):  
Quantum Chromodynamics ◽  
Quantum Electrodynamics ◽  
Charged Particles ◽  
Dominant Effect ◽  
Self Energy

The electromagnetic self-energy of charged particles has remained a problem in classical as well as in quantum electrodynamics. In contrast here, in a review of the analysis of the chromodynamic self-energy of quarks in quantum chromodynamics (QCD), we see that the quark self-energy is a finite and a dominant effect in determining the structure of hadrons.

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