Coupling of spin to an electric field

[Asaba E]

Hi PF members. I have got a little worry
I am familiar with the Zeeman term that always appears in the Hamiltonian of a spin chain representing the influence of an external magnetic field. I don't know if there is a similar term if the spin was rather in he presence of an electric field ( I just think if the electric field has effects on the spin, then those effects would be as important as those of the magnetic field). I have not come across any good literature on this. could some one point me in the right direction?

 

[Avodyne]

A coupling of spin to the electric field (in the usual way that a magnetic field is coupled) would violate both parity and time-reversal invariance, and hence is expected to be extremely small in most circumstances. For a single electron, see http://en.wikipedia.org/wiki/Electron_electric_dipole_moment

It seems to me that it could happen in some sufficiently complicated material, but I don't know of any examples.

 

[sadraj]

I think by writing Dirac equation (Relativistic counterpart of Schrodinger equation) and see it's low velocity limit , one find that spin just couples to magnetic part of the Gauge field. It is so strange that Electric field also couples to spin in low energy regime!

 

[Asaba E]

Thanks. I have always had the same view that the coupling of the electric field to spin would be very small hence negligible. Recently I came across an article discussing the effects of an electric field on spin wave dispersion relation in multiferriocs.(doi:10.4236/wjcmp.2012.24037 Published Online November 2012 (http://www.SciRP.org/journal/wjcmp) . I have been wondering within what limits can one consider the effects of an Electric field on the dynamics of spin chains?

 

[ChrisVer]

http://www.sciencemag.org/content/318/5855/1430.abstract

for example what about this?

 

[Bill_K]

http://www.sciencemag.org/content/318/5855/1430.abstract for example what about this?

It's also here: http://arxiv.org/abs/0707.3080. They explain it as an indirect effect mediated by spin-orbit coupling:

Although electric fields do not couple directly to the electron spin, indirect coupling can still be realized ... through spin-orbit interaction, present in most semiconductor structures.
...
An electric field E(t) will periodically and adiabatically displace the electron wave function, so the electron spin will feel an oscillating effective field B_eff(t) through the dependence of B_eff on the position.