diff --git a/roam/data/d6/e44fbc-975b-463d-87f9-878d50758b55/index.tex b/roam/data/d6/e44fbc-975b-463d-87f9-878d50758b55/index.tex index bc53a37..d794da4 100644 --- a/roam/data/d6/e44fbc-975b-463d-87f9-878d50758b55/index.tex +++ b/roam/data/d6/e44fbc-975b-463d-87f9-878d50758b55/index.tex @@ -32,12 +32,30 @@ system \(A\) and a transmission line \(B\). The \(A\) system is considered to have the Hamiltonian \begin{equation} \label{eq:1} - H_{A}=H_{0}+V(t) = ∑_{m} ω^{0}_{m} c_{m}^†c_{m} + V(t), + H_{A}=H_{0}+V(t) = ∑_{j,β;i,α} \pqty{H_{0}}_{i,α;j,β}a_{j,β}^†a_{i,α}= ∑_{m} ω^{0}_{m} c_{m}^†c_{m} + V(t), \end{equation} -where we are working in the basis that diagonalizes \(H_{0}\) and the -\(c_{m}\) are linear combinations of the bare modes in the photonic -system. We designate the bare modes of the EM field that are actually -in contact with the transmission line as \(a_{β}\) with +where \(\comm{a_{i,α}}{a^†_{j,β}}=δ_{ij}δ_{αβ}\). We assume that the +system \(A\) consists of several distinct resonators/cavities indexed +by the first index on the \(a^†\), who each have their own lengths +\(L_{A,i}\) and eigen-momenta \(k_{i,α} = 2πα/L_{A,i}\) with +\(α\in\ZZ\). + +The eigenmodes of the system \(c_{m}\) are linear combinations of the +bare modes in the photonic system where we have +\begin{equation} + \label{eq:43} + c_{m} = ∑_{i,α} T^\ast_{i,α;m}a_{i,α}, +\end{equation} +where \(T_{i,α;m}\) is the matrix whose rows are the normalized +eigenvectors of the matrix \(\pqty{H_{0}}_{i,α;j,β}\). + + +We designate the bare modes of the +EM field that are actually in contact with the transmission line as +the modes with subsystem index \(i=i_{0}\) which is suppressed for +clarity in all expressions concerning that subsystem. We find modes +\(a_{β}\) for the electric field in the subsystem in contact with the +transmission line \begin{equation} \label{eq:4} E_{A}(x,t)= \iu \sqrt{\frac{\hbar}{2ε_{0}n_{A}^{2} L_{A,\perp}^{2} L_{A}}} ∑_{β} @@ -58,11 +76,11 @@ can be related through \label{eq:5} a_{β} = ∑_{m} U_{βm} c_{m}, \end{equation} -where \(U\) is a not necessarily square matrix that obeys the -unitarity relation \(U U^† = \id\). Transitioning into a rotating -frame with respect to \(H_{0}\) and employing the rotating wave -approximation removes all but the slowest-oscillating rotating terms -from the interaction +where \(U_{βm} = T_{i_{0},β;m}\) is a not necessarily square matrix +that obeys the unitarity relation \(U U^† = \id\). Transitioning into +a rotating frame with respect to \(H_{0}\) and employing the rotating +wave approximation removes all but the slowest-oscillating rotating +terms from the interaction \begin{equation} \label{eq:12} \tilde{c}(t)_{m} = c_{m}(t)\eu^{\iu ω^{0}_{m}t} \implies H_{A} \to \tilde{H}_{A}= @@ -551,6 +569,21 @@ position \(x>0\) we have \end{equation} with \(b_{\inputf}(s) = b_{\inputf,+}(s) + b_{\inputf,-}(s) = b_{\inputf,+}(s)\). +\subsection{Langevin-Equations for Lossy Oscillators} +\label{sec:lang-equat-lossy} + +In the above we have assumed that \(H_{0}\) is hermitian. This, +however, ceases to be the case when we assume some a-priori +phenomenological decay in the bare components of the system and we +cannot write \(H_{0}=H^{H}_{0} - \iu η \id\) with \(H^{H}_{0}\) +hermitian. + + + + + + + \section{Application to the Non-Markovian Quantum Walk} \label{sec:appl-non-mark} The experimental setup for implementing the non-Markovian quantum walk