where σ+ n = |e n ⟩⟨g n | and σn = |g n ⟩⟨e n | are the creation and annihilation operators of the n th molecule's exciton, and ω 0 is the excitation energy between the molecule's ground and excited state. The corresponding reorganization energy λ accounts for the energy shift due to excitonphonon coupling, which is described in the system-bath interaction ĤSB (see Eq. 7). The cavity Hamiltonian Ĥcav describes the quantized radiation field