Secondly, modulation of the isomerization process is correlated with the changes in the phase space features with varying cavity frequency. Thirdly, the phase space nature of the polariton states, formed due to cavity-system coupling, that contribute to the dynamics are consistent with the observed initial state dependence. Finally, for initial states corresponding to a dark cavity we find quantum suppression of the isomerization around ω c ≈ ω 10 , irrespective of the initial state. In the dark cavity case, given that only the X 0 and the X 1 doublets are relevant, it may be possible to gain further understanding based on the work of Llorente and Plata. A detailed understanding of tunnelling modulation in twolevel systems coupled to cavity modes, including under dissipative conditions , already exists. Perhaps some of the results in this context may provide additional in- The notations are as in Fig. .