Quantum Spin

Intrinsic angular momentum carried by particles with no classical rotation behind it, quantized in half-integer steps.

Core Principles & Analysis

• Uhlenbeck and Goudsmit proposed electron spin in 1925 to explain doublet spectral lines.
• Stern and Gerlach had already seen its two-valued deflection in 1922 without knowing what it was.
• The spin-statistics theorem splits the world in two: half-integer spins obey exclusion, integer spins condense.

Specifications & Metrics

• SYMBOL: S_z = ±ħ/2