Figure 4

Coupled oscillator model and the fitting to numerical data.
(a) Schematic of the coupled oscillator model for the AM-CM interactions. The coupling coefficient between the AM and CM10 is κ. Their individual resonance spectra are schematically shown at the right side. (b) The σECS spectrum of the PDA numerically calculated by the FIT (circles) and the fitted result from the coupled oscillator model (line).