Are Bound States Always Entangled in Quantum Mechanics?

[metroplex021]

Hi folks -- quick question. I appreciate that entangled states in quantum mechanics may not be bound states. But when we have bound states, are the particles always entangled with one another?

Thanks a lot!

 

[Khashishi]

Depending on who you ask, everything is entangled. But, yeah, particles that are bound together are very strongly coupled and will behave as entangled. For example, light atoms usually obey LS coupling, so you lose information if you just look at the electron alone and not the full atom.