FIG. 4.

Absorption spectra of the benzaldehyde molecule from TDA-JC (solid lines) and two-state Jaynes–Cummings model (dotted-dashed lines) calculations with different coupling strengths using the PBE0 functional and 6-311++G** basis set. The Fabry–Pérot mode is chosen to be (a) in resonance (4.879 eV) and (b) 0.02 eV off-resonance (4.899 eV) from the gas-phase excited state. The blue and orange lines indicate the electron and photon contributions, respectively. Following Ref. 91, Lorentzian broadening is employed with Δ = 10⁻² eV.