Register to reply 
Is there a direct magnetic interaction between two electrons? 
Share this thread: 
#1
Jun311, 08:06 AM

P: 4

Spin orbit coupling accounts for the relative motion of a magnetic moment interacting with an electric field.
Is there a direct coupling of the magnetic moments of, say, the electrons in an atom as well? Does a magnetic field emanate from spin 1/2 particles in general? Thank you for reading this. 


#2
Jun311, 11:09 AM

P: 679

I believe there is, just like hyperfine structure involves spinspin interaction of electron and nucleus, but I have not seen any calculations on spinspin interaction between eletrons in textbooks.



#3
Jun311, 04:44 PM

Sci Advisor
P: 1,261

Any particles with magnetic moments, including electrons have a spin.spin interaction energy. It could occur for electrons in atoms, and is important for quarks in baryons. Hyperfine splitting in atoms is affected by the spin.spin interaction of the nucleus and an orbiting electron.



#4
Jun311, 04:56 PM

P: 11

Is there a direct magnetic interaction between two electrons?
Check:
http://en.wikipedia.org/wiki/Hyperfi...agnetic_dipole It has an expression for the magnetic coupling between an electron the nuclei but the same expression is also used for electronelectron magnetic coupling. 


#5
Jun311, 08:46 PM

Sci Advisor
P: 1,395

Typically, for electrons in atoms, we talk about coupling of angular momentum (e.g. spin orbit coupling), rather than magnetic interaction, between electrons. However the effects are not really separable .. part of the magnetic moment of the electrons in atoms arises from their intrinsic angular momentum in the first place.
For multielectron atoms, you can use angular momentum coupling rules to come up with term symbols for the electronic states. These term symbols use angular momentum coupling rules to associate angular momentum quantum numbers for the total angular momentum, orbital angular momentum, and spin angular momentum of the overall electronic wavefunction. The total angular momentum (quantum number J), is always a good quantum number (neglecting the nuclear hyperfine interaction), but the orbital angular momentum quantum number (L) and spin angular momentum quantum number (S), are only approximately good (at best). By the way, a "good" quantum number is one corresponding to an operator that commutes with the Hamiltonian ... an "approximately good" quantum number corresponds to an operator that does not strictly commute with the Hamiltonian, but where the coupling is small compared to the energy level spacing. If the spinorbit interaction is particularly large, it doesn't even make sense to talk about overall orbital angular momentum (L) and overall spin angular momentum (S) any more. Rather, it is more appropriate to couple the orbital (l) and spin (s) angular momenta to obtain a total angular momentum (j) for each individual electron, and then treat the coupling of these angular momenta to obtain the overall total angular momentum (J). This scheme is called jj coupling. Anyway, the point of all of this is that the magnetic dipole of an atom can be determined from the total angular momentum quantum number, taking into account the angular momentum coupling according to the Lande gfactor. The wikipedia pages on this stuff are pretty good. If you are interested, you might want to look at the ones on the electron magnetic dipole moment, Term symbols, and angular momentum coupling to start. 


#6
Jun511, 10:44 AM

P: 9

not if you could get to absalute zero and stop the spin of the electron at atomic level all magnetic feilds would not exist.



#7
Jun511, 11:32 AM

P: 434

As a side question: doesn't it depend on frame of reference? For two electrons in rest, there is only electrostatic repell between them. But if we change our frame so that they start moving, they will produce electric current and thus magnetic attraction.
Someone here said some time ago, that photons and gauge bosons in general are not frameindependent, but obey gauge symmetries. So I can believe that there are photons in one frame and not in the other, but I still have problems understanding it. 


#8
Jun511, 12:07 PM

Sci Advisor
P: 1,395




#9
Jun511, 01:17 PM

P: 434

So we can have attracting or repelling particles depending on the frame we choose. I completly miss something here. 


#10
Jun511, 01:24 PM

Sci Advisor
P: 1,395




#11
Jun511, 05:39 PM

Sci Advisor
P: 1,261

Nothing can stop it spin. 


#12
Jun511, 05:42 PM

Sci Advisor
P: 1,261




#13
Jun511, 06:34 PM

Sci Advisor
P: 1,395

Has anyone studied the interactions of charged, spinzero mesons? Do they even exist long enough for such studies to be undertaken? I guess there would be no Pauliprinciple for such particles (since they are bosons). In fact, I guess in principle you could even have a BEC of charged mesons, if they hung around long enough to be cooled and trapped. Ok .. I will shut up now .. the water is way deeper than my head and there may be sharks coming 


#14
Jun511, 07:20 PM

Sci Advisor
P: 1,261




Register to reply 
Related Discussions  
Magnetic interaction  Atomic, Solid State, Comp. Physics  0  
Moving charge in a magnetic field, magneticmagnetic interaction?  General Physics  6  
Magnetic field interaction  Classical Physics  1  
Electrostatic magneticfield interaction  General Physics  8  
Fermi Interaction of Electrons with Nuclei  Quantum Physics  6 