] at resonance, where |D J , 0⟩ is the state where the J th molecule is in its donor excited state while the rest of the molecules are in their ground states. The consequence of the 1/ √ 2N factor in front of the donor states in Eq. 211 is that the reorganization energy of these polariton states is proportional to the donor reorganization energy times 1/N . This can be seen as a shift of the polariton parabolas towards the ground state configuration (which is closer to the acceptor state) as N increases (Fig. ). In the limit of large N , this polariton reorganization energy goes to 0, which is known as polaron decoupling. Note that this effect also applies to the donor dark states, but does not apply to the acceptor states, which are uncoupled from the cavity in this example and thus retain their original reorganization energy relative to the ground state.