Physicists trace origin of electromagnetic interaction to Dirac equation

An international group of physicists has traced the origin of an electromagnetic interaction to the Dirac equation, a fundamental equation of quantum physics.

The interaction couples the spin of the electron to the of the and it is responsible for a variety of phenomena in a large class of technologically important materials. University of Arkansas researchers proposed the interaction in 2013.

In addition to charge, electrons have spin. By understanding and using the different states achieved when an electron's spin rotates, researchers could potentially increase information storage capacity in computers, for example.

The new finding, published as a rapid communication in the journal Physical Review B, advances the fundamental understanding of magnetic systems as well as multiferroics, which can change their electrical polarization when in a magnetic field or when in an electric field. The rapid communications section of Physical Review B, a journal of the American Physical Society, is devoted to the accelerated publication of especially important new results.

"Through this interaction, magnetic moments can generate an and an electric polarization can generate a magnetic texture in multiferroics," said Laurent Bellaiche, Distinguished Professor of physics at the University of Arkansas. "This provides another handle on how material properties can be tuned or controlled for practical applications in devices based on electrical and magnetic properties."

Surendra Singh, professor of physics, and Bellaiche were part of the U of A team that proposed in 2013 that the angular momentum of an electromagnetic field can directly couple to the spin of an electron to produce a physical energy. This direct coupling explains known, subtle phenomena in magnetoelectric materials and predicts effects that have not yet been experimentally observed.

"For a long time, scientists explained these effects by using only the so-called spin-orbit coupling," Singh said. "Our paper shows that the angular magnetoelectric interaction also contributes to these effects and that this term, along with spin-orbit coupling, follows naturally from a more exact theory of electron-light. It just had been ignored for so long."

The results were obtained through a collaborative effort with two other groups – Ritwik Mondal, Marco Berritta and Peter M. Oppeneer at Uppsala University in Sweden and Charles Paillard and Brahim Dkhil at Ecole Centrale of Paris in France.

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More information: Relativistic interaction Hamiltonian coupling the angular momentum of light and the electron spin, Phys. Rev. B 92, 100402(R) – Published 11 September 2015
Journal information: Physical Review B

Citation: Physicists trace origin of electromagnetic interaction to Dirac equation (2015, October 12) retrieved 15 July 2019 from
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Oct 12, 2015

This paper explains the magnetic effect of the electric current from the observed effects of the accelerating electrons, causing naturally the experienced changes of the electric field potential along the electric wire. The accelerating electrons explain not only the Maxwell Equations and the Special Relativity, but the Heisenberg Uncertainty Relation, the wave particle duality and the electron's spin also, building the bridge between the Classical and Quantum Theories. New ideas for interactions and particles: This paper examines also the possibility to origin the Spontaneously Broken Symmetries from the Planck Distribution Law. This way we get a Unification of the Strong, Electromagnetic, and Weak Interactions from the interference occurrences of oscillators.

Oct 12, 2015
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Oct 12, 2015
Consider the Poynting vector in a 4D space. Present definition does not define the velocity of the field. The Poynting vector about any charge carries the normal vector at a point of the sphere, 1/r^2, about the charge + the Poynting vector of the charge. Spin is an illusion!

Oct 13, 2015
Well stated, Hyperfuzzy! Problem is; the rest of the world is too well indoctrinated to see the proverbial 'Wood' from the 'Trees'!

Oct 13, 2015
The confusion is rather bizarre, the propagation constant, lambda nu = c has nothing to do with the relationship of any field relative to any point in space time. The "speed" of light is an unknown. Obviously if one is trying to measure time dilation would simply change distance and time, but is not relevant. The Dirac function, however is very useful, I used it to help define the propagation of a Gaussian beam in an inhomogeneous medium. I knew that if I used a larger order I might be more definitive, but never precise without a better definition of the actual point motion. The best speed we can derive is: Lambda.emitted /

Oct 13, 2015
Anyway, spin can only be approximated as a tiny charge moving about a sphere, or circular motion, no matter how small the sphere becomes, it is angular motion, not spin; so calling spin as something different than angular motion is redundant, of course it's the same thing. Something like the slit experiment. Particles create waves. Same experiment, same source. An experiment misinterpreted. Obviously a PhD can see this or at least correct himself after 100 years. We, all, are not misinformed. Some of us have moved beyond the 20th century, it's like trying to prove the earth is flat, by example, using only the plains!

Oct 16, 2015
All jokes aside, it is a rather complex problem. Consider a unit hyper-sphere. Why would any action within this sphere be different from action within an infinite hyper-sphere? In other words, scale. If the "+&-" occupy no volume then ... ??? The idea is an infinite number may exist within a unit hyper-sphere. Hence should we consider our infinite space as simply a unit sphere? This infers a mathematical 5th dimension but is only isomorphic to reality. Don't want to make the same mistakes of the past by given names to what we do not understand. Hence the little "+&-" ... still working to define a proper space, so far it is not E's or CERN's. You may simply use Maxwell everywhere. But the real game is the definition or explanation of the "+&-", not by collision!

Note: Normalization!

Oct 16, 2015
Its always the fields of the collective centers, both positive and negative and exist everywhere for these particles are neither created or destroyed! Relative to each, the field is perfectly spherical, wither in motion or stationary. Acceleration and motion everywhere is continuous, has been continuous, and will be contentious. All collections seek a stable state. Any point in the field may be modeled as another point located at "r" such that E is the same and the direction is always normal to the sphere at that "ghost" point. The field may be defined at each point alone the time-line based upon change of position among 0-, 0, 0+. Our "space" may be modeled as a 4D space, unitless, i.e. unit -->ct

Oct 16, 2015
Therefore, everything may be defined as the supposition of only the "+" field and the "-" field at each [x1, x2, x3, x4]! Then we will let the computer check out Dirac's brilliance.

But then he wasn't seeking truth, he just wanted to get close; didn't have the tools! That's what discovery is, use what you've got! But don't let old tools slow you down.

And please use logic. You can't use the thing your are trying to prove as your only instrument of proof without supplying an alternative, at least a diametrical argument with a non-existence proof, or som'n som'n ... professional paper, but I would reject it, based upon the title. maybe, rename! In fact, time travel ... what would you rename?

Now where was I, oh the normal of the hyper-sphere? Simple, any line through the center ...

Oct 16, 2015
Why not simply define each particle as some sort of magnitude * unit-hyper-sphere, or ... memory/time, hmmm, smart memory!

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