The total Hamiltonian can be written in the diabatic representation as: In the isolated system, the energy bias and the electronic inter-state coupling between the two diabatic electronic states are 𝜖 0 and 𝜈 0 , respectively, where 𝜎 𝑥,𝑦,𝑧 are the usual Pauli matrices and 𝑰 2 is the identity matrix of size 2. The coupling constants (𝑔 𝑗 ) between the system and bath are determined by the spectral density: