Cavity QED — Strong Coupling & Polaritons

An atom coupled to a cavity mode with coupling g forms upper and lower polariton branches. In the strong-coupling regime g > (κ,γ)/2, the vacuum Rabi splitting 2g becomes visible in the transmission spectrum. Jaynes–Cummings Hamiltonian: H = ωₐσ⁺σ⁻ + ωₒa⁺a + g(σ⁺a + σ⁻a⁺).

Coupling g (MHz)g = 10 MHz

Cavity decay κ (MHz)κ = 3 MHz

Atom decay γ (MHz)γ = 1 MHz

Detuning Δ (MHz)Δ = 0 MHz