Cavity QED: Jaynes-Cummings Entanglement
Atom-field dynamics, collapse & revival, entanglement entropy, Wigner function
Jaynes-Cummings Model: H = ωaᵀa + (ω₀/2)σz + g(aσ₊ + aᵀσ₋) + Δ·σz.
Starting with atom excited |e⟩ and field in coherent state |α⟩: Rabi oscillations collapse (dephasing by photon number spread),
then revive at t_rev = 2π√n̄/g. Bottom left: P(e) — collapse/revival. Right: entanglement entropy S = −Tr(ρ_atom ln ρ_atom). Wigner function of field state shown center.