Paired electrons in a magnetic field

[anorred]

What would happen if you place a substance containing bonded and paired electrons, such as a biological organ, and place that substance in a homogenous magnetic field? Would the electrons align with the field?

I'm a little confused by what an electron pair is. I pretty much know the pauli exlusion principle, but maybe I'm not interpreting it correctly. I'm an engineer, not a physicist, so please educate me!

 

[mfb]

As long as they are paired in the same energy state, their net orientation is always zero. If you break them up and measure their orientation, you'll find it aligned with the magnetic field.

 

[anorred]

Alright. So let's say you use magnetic resonance on paired electrons with EM waves. Do you think they would absorb energy more than other electrons that have a different resonation frequency? I know you wouldn't be able to image/read paired electrons signals because they would cancel out, but I'm just wondering if they would absorb more energy.

 

[mfb]

Paired electrons don't care about magnetic fields, and I don't see where you see a resonance or any reaction at all.

 

[f95toli]

I think the word "pair" is a bit ambigous. Normally, when people talk about electron pairs they mean something like Cooper pairs in superconductors. In this case you can certainly break the pair with a hight enough field; the spin-pair breaking field is reached when the Zeeman energy is equal to the pairing energy of the electron.
In addition to this you can also have orbital pair breaking, where the Lortentz force separats the electrons until the pair splits, the electrons will always move in opposite directions since they have opposite spins.

 

[anorred]

Great answers thank you very much!