On the relativistic L-S coupling
arXiv:physics/9809015 · doi:10.1088/0143-0807/19/6/008
Abstract
The fact that the Dirac equation is linear in the space and time derivatives leads to the coupling of spin and orbital angular momenta that is of a pure relativistic nature. We illustrate this fact by computing the solutions of the Dirac equation in an infinite spherical well, which allows to go from the relativistic to the non-relativistic limit by just varying the radius of the well.
LateX2e, 12 pages, 1 figure, accepted in Eur. J. Phys