Fig. 4: Extracting the Huang–Rhys factor.
From: Magnetically brightened dark electron-phonon bound states in a van der Waals antiferromagnet
On the left, phonon eigenstates with equal spacings are shown. Coupling between the d–d transition and phonon degrees of freedom gives rise to a broad peak in absorption with an oscillatory feature on top as well as an energy renormalization denoted by Δ. This model matches well with the experimental data. We fit the absorption spectrum with a minimal model which consists of a sum of linewidth functions (Gaussian or Lorentzian) weighted by a Poisson distribution. The free parameter of this distribution corresponds to the dimensionless Huang–Rhys factor g.
