Can different forms of angular momentum be converted into each other?

Question

I am aware of three apparently different forms of angular momentum: spin, orbital and macroscopic, like a spinning crystal or baseball. Can angular momentum be transferred or converted from one of these forms to another? If so, how?

possible duplicate of Can spin and macroscopic angular momentum convert to each other? — Qmechanic, Feb 05 '12 at 20:10

score 3 · Accepted Answer · answered Jul 24 '11 at 04:13

3

Are you looking for something like the Einstein-de Haas effect? The angular momentum of the spins in a ferromagnet is converted to mechanical angular of the bulk magnet.

answered Jul 24 '11 at 04:13

BebopButUnsteady

6,837

score 1 · Answer 2 · answered Jul 24 '11 at 04:30

1

the different "forms" of angular momentum are still the same fundamental thing, they are just generated in different manners. there is a big difference in how spin, orbital and classical angular momenta are created... but it's still same units of action for all of them (I believe). to convert from one "form" to another therefore would be like asking how to convert from one type of kinetic energy to another... i'm sure there are example of angular momentum transfer--- just examine hydrogen state transitions for example

answered Jul 24 '11 at 04:30

Timtam

862

to be more specific, suppose a hydrogen atom transitions to a higher energy state when a photon hits it, the photon is spin 1, so all of that is converted into whatever angular momentum state the hydrogen atom transitions to for example it may transition from l=1 to l=2 state in that case, this example shows spin 1 state being annhilated and the result being a net increase in orbital angular momentum--- (there may be some details i am missing--- it would be nice to see an explicit argument/example if someone can provide that of somthing similar) – Timtam Jul 24 '11 at 04:39

Can different forms of angular momentum be converted into each other?

2 Answers2