Is fractional orbital momentum theoretically possible?

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Discussion Overview

The discussion revolves around the theoretical possibility of fractional orbital angular momentum, exploring whether existing laws of physics would need to be altered to accommodate such a concept. The scope includes theoretical considerations and implications for both light and charged particles.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions the theoretical possibility of fractional orbital angular momentum and asks what laws of physics would need to change to allow it.
  • Another participant suggests that anyons might be relevant, but expresses uncertainty, stating that real electrons cannot have fractional orbital momentum.
  • A different participant clarifies that they are not discussing anyons or spin, but specifically orbital angular momentum, and reiterates the question about necessary changes to physical laws.
  • It is proposed that nothing needs to change for the orbital angular momentum of light, which can exhibit fractional values without violating conservation of momentum.
  • One participant suggests measuring angular momentum in units of 2 hbar as a potential approach to fractional values.
  • Another participant notes that angular momentum can become non-integer for spinless charged particles in the presence of a magnetic field.

Areas of Agreement / Disagreement

Participants express differing views on the possibility of fractional orbital angular momentum, with no consensus reached on whether it can occur in real electrons or what changes to physical laws would be necessary.

Contextual Notes

The discussion includes assumptions about the nature of angular momentum in different contexts, such as light and charged particles, and the implications of magnetic fields, which remain unresolved.

haael
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It bugs me: is it theoretically possible for orbital angular momentum to take fractional values? Which laws of physics should be changed to get that?
 
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I think http://en.wikipedia.org/wiki/Anyon" can. But I'm not sure, it's not really my area.

Real electrons in real atoms? I don't think so.
 
Last edited by a moderator:
No, no. I'm not talking about real electrons (I'm sure they can not have fractional orbital momentum). I'm not talking about anyons, either. They can just have nonstandard phase under 360 deg. rotatios, but it's still all about spin.

Alas, I'm not talking about spin, but about orbital angular momentum. What should be changed in our laws of physics to have fractional orbital momentum possible?
 
haael said:
No, no. I'm not talking about real electrons (I'm sure they can not have fractional orbital momentum). I'm not talking about anyons, either. They can just have nonstandard phase under 360 deg. rotatios, but it's still all about spin.

Alas, I'm not talking about spin, but about orbital angular momentum. What should be changed in our laws of physics to have fractional orbital momentum possible?

Nothing need be changed if you are talking about orbital angular momentum of Light. Most folks don't realize light can be created with orbital angular momentum.: http://www.aip.org/png/2005/229.htm

Apparently it can be fractional, and without violating COM...

http://books.google.com/books?id=Vf...q=fractional orbital angular momentum&f=false

...
 
Last edited by a moderator:
haael said:
What should be changed in our laws of physics to have fractional orbital momentum possible?
Measure in units of 2 hbar.
 
Angular momentum becomes non-integer even for spinless charged particles once a magnetic field is present.
 

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