In this section, we use the mixed HEOM-Lindblad formalism (see Sec. I of the Supplementary Material) to simulate the LA spectra of the single mode 1D HTC model. The reduced system part is restricted in the ground and first excited manifolds under the diabatic basis (see Eq. 12), and ĥB is treated as bath DOF. We briefly summarize the main model parameters used in numerical simulations in Table , which lead to a dimensionless parameter of κ N ≈ 1. √ N (see Eq. 28), so that the bath is in the fast limit as N increases. The bath parameters lead to a bare exciton linewidth of about Γ ex ≈ 76.5 meV. Note that under the room temperature of T = 300 K, the thermal energy is about k B T ≈ 26 meV. The LA spectra can be directly computed from the Fourier transform of the dipole-dipole correlation function according to