spectral.susceptibility_two_linear_known

spectral.susceptibility_two_linear_known(
    freq_list,
    interaction_strength,
    decay_rate,
)

In the linear regime for a two-level system, the susceptibility is known analytically. This is here for useful comparison, as good agreement between a simulated weak field in a two-level system tells us that the model is accurate in the linear regime, which gives us confidence in the scheme for going beyond the weak field limit.

Notes

Returns g·χ_ρ, where χ_ρ is the coherence susceptibility satisfying ρ₀₁ = χ_ρ·Ω in the weak-field limit. The Bloch Hamiltonian uses the standard coupling Ω/2, so χ_ρ = i/(Γ/2 − iΔ). The absorption and dispersion are its imaginary and real parts respectively. See TP Ogden Thesis Eqn(2.61).