Electron oscillation between states

[jjurbanus]

Hi, it's been awhile since taking a quantum mechanics course, but I thought I read somewhere that during an electron decay into a lower stationary state, it can be shown to literally oscillate between the states momentarily, hence providing a clear source of acceleration in a kind of oscillator motion for the creation of the emitted radiation. Did I dream this? It seems if I didn't, it should be more prevalent in explanations of decay and photon emission.

 

[Bill_K]

Don't believe everything you read. You probably did read that somewhere, but it's an old pre-quantum-mechanical way of attempting to explain discontinuous quantum transitions in terms of continuous classical processes. The modern (since ~ 70 years) viewpoint is that while the probability of finding the electron in the final state does increase continuously, the transition itself is instantaneous.

 

[strangerep]

The modern (since ~ 70 years) viewpoint is that while the probability of finding the electron in the final state does increase continuously, the transition itself is instantaneous.

Actually, I remember my 3rd yr QM lecturer deriving something similar to what the OP said. I think it was some kind of time-dependent perturbation approach to an atom interacting with a radiation field. He was able to show that the (time dependent) position distribution for the electron did indeed oscillate on its way down from a higher energy state to a lower one, and that the oscillation frequency corresponded to the emitted photon (i.e., energy difference between the states).

Can't find a reference though. :-(

 

[Chopin]

Isn't that just a standard problem in non-relativistic QM? Pretty much every text I've seen talks about this during its discussion of time-dependent perturbation theory (a Google search brought up http://www.ecse.rpi.edu/~schubert/Course-ECSE-6968%20Quantum%20mechanics/Ch11%20Time-dependent%20perturb.pdf , which discusses it in section 11.3).

That's pretty much the best you can do in non-relativistic QM, since there's no way in that framework to talk about the emission/absorption of a photon. QFT can do better, since both the electron and the EM field are described by quantum variables, and particle number can change.

 

[jjurbanus]

Hi, it looks like I didn't dream it!

http://www.attoworld.de/Home/attoworld/ElectronsAndLight/EmissionOfPhotons/index.html

 

[jjurbanus]

Thanks strangerep and Chopin :)