Spin-Orbit Interactions

In Quantum Physics, the spin-orbit interaction (or spin-orbit coupling) is a relativistic interaction of a particle's spin with its motion inside a potential.

A key example of this phenomenon is the shift in an electron's atomic energy levels from to spin-orbit interactions, due to electromagnetic interactions between the electron's magnetic dipole, it's orbital motion and the electrostatic field of the positively charged nucleus. This phenomenon is detectable as the splitting of spectral lines, also though of as a Zeeman Effect product of two relativistic effects - The apparent magnetic field seen from the electron's perspective and the magnetic moment associated with the electron due to its intrinsic spin.

A similar effect occurs for protons and neutrons moving inside the nucleus, due to the relationship between angular momentum and strong nuclear force, leading to a shift in their energy levels in the nucleus shell model.

This is studied in the field of Spintronics.

Other

This can also refer to Tidal Locking in astronomy, which is also known as spin-orbit locking.