From this and Equation (???), we identify the corresponding classical field \[\mathbf{A}(\mathbf{r},t) = \sum_{\mathbf{k}\lambda} \Big(\mathcal{A}_{\mathbf{k}\lambda}\, e^{i(\mathbf{k}\...From this and Equation (???), we identify the corresponding classical field A(r,t)=∑kλ(Akλei(k⋅r−ωkt)+c.c.)ekλ,whereCkλαkλ=Akλ. For each k and λ, Equations (???)–\(\eqref{B…