Quantum Harmonic Lattice
1D phonon chain: dispersion relation, zero-point energy, Bose-Einstein occupation
1D monatomic chain: ω(k)=2√(κ/m)|sin(ka/2)|. Quantum occupation: ⟨n_k⟩=1/(e^{ℏω_k/k_BT}−1) (Bose-Einstein). Zero-point energy: ½ℏω per mode, persists at T=0. The lattice animation shows each mode as a classical wave weighted by √(⟨n_k⟩+½) — quantum amplitude. Blue=quantum zero-point contribution, orange=thermal.