Electron Spin
An intrinsic form of angular momentum carried by elementary particles, independent of orbital spatial motion.
Governing formula
S = √(s (s + 1)) ℏ, s = ½, S_z = ± ½ ℏ
SI unit
J·s (Spin Angular Momentum)
In depth
Spin is a fundamental relativistic quantum property without a classical spinning object analogue. Electrons possess intrinsic spin s = 1/2, generating a spin magnetic dipole moment μ_s = -g_e (e / (2 m_e)) S.
Examples in the real world
Nuclear Magnetic Resonance (NMR) and Medical MRI imaging detecting proton spin precession in magnetic fields.