Figure 2

The absorption spectrum of signal laser and the energy levels of exciton when a single peptide QD coupling with the vibration of DNA molecules. (a) The absorption spectrum of signal laser in the presence of two optical fields for the case ${\Omega }_{c0}^2=2$, Δ_{c 0}= 0, λ₀ = 0.5, ω_{D 0}= 4, τ _D 0 = 33. (b) The energy levels of exciton when coupling with the vibration of DNA molecules. Part (2), (3), and (4) correspond to the transitions of the left peak, center feature and right peak, respectively, shown in (a).