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author | Prefetch | 2024-07-17 10:01:43 +0200 |
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committer | Prefetch | 2024-07-17 10:01:43 +0200 |
commit | 075683cdf4588fe16f41d9f7b46b9720b42b2553 (patch) | |
tree | f200b341b35e9c89aa1030a2f6da94cd0e1e958b /source/know/concept/maxwell-bloch-equations | |
parent | c4d597e8d695eb145755464cffbf88a68fd0c88a (diff) |
Improve knowledge base
Diffstat (limited to 'source/know/concept/maxwell-bloch-equations')
-rw-r--r-- | source/know/concept/maxwell-bloch-equations/index.md | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/source/know/concept/maxwell-bloch-equations/index.md b/source/know/concept/maxwell-bloch-equations/index.md index 1214703..28885af 100644 --- a/source/know/concept/maxwell-bloch-equations/index.md +++ b/source/know/concept/maxwell-bloch-equations/index.md @@ -17,8 +17,8 @@ where $$\varepsilon_g$$ and $$\varepsilon_e$$ are the time-independent eigenener and the weights $$c_g$$ and $$c_g$$ are functions of $$t$$: $$\begin{aligned} - \ket{\Psi} - &= c_g \ket{g} e^{-i \varepsilon_g t / \hbar} + c_e \ket{e} e^{-i \varepsilon_e t / \hbar} + \ket{\Psi(t)} + &= c_g(t) \ket{g} e^{-i \varepsilon_g t / \hbar} + c_e(t) \ket{e} e^{-i \varepsilon_e t / \hbar} \end{aligned}$$ This system is being perturbed by an electromagnetic wave @@ -32,8 +32,8 @@ $$\begin{aligned} Where the forward-propagating component $$\vb{E}^{+}$$ is a modulated plane wave $$\vb{E}_0^{+} e^{-i \omega t}$$ with slowly-varying amplitude $$\vb{E}_0^{+}(t)$$, -and similarly $$\vb{E}^{-}(t) \equiv \vb{E}_0^{-}(t) e^{i \omega t}$$; -since $$\vb{E}$$ is real, $$\vb{E}_0^{+} \!=\! (\vb{E}_0^{-})^*$$. +and similarly $$\vb{E}^{-}(t) \equiv \vb{E}_0^{-}(t) e^{i \omega t}$$. +Since $$\vb{E}$$ is real, $$\vb{E}_0^{+} \!=\! (\vb{E}_0^{-})^*$$. For $$\ket{\Psi}$$ as defined above, the pure [density operator](/know/concept/density-operator/) @@ -92,7 +92,7 @@ $$\begin{aligned} \end{aligned}$$ However, the light wave affects the electron, -so the actual electromagnetic dipole moment $$\vb{p}$$ is as follows, +so the true electromagnetic dipole moment $$\vb{p}$$ is as follows, using [Laporte's selection rule](/know/concept/selection-rules/) to remove diagonal terms by assuming that the electron's orbitals are spatially odd or even: @@ -106,9 +106,9 @@ $$\begin{aligned} \\ &= q \Big( \rho_{ge} \matrixel{e}{\vu{x}}{g} + \rho_{eg} \matrixel{g}{\vu{x}}{e} \Big) \\ - &= \vb{p}_0^{-} \rho_{ge}(t) + \vb{p}_0^{+} \rho_{eg}(t) + &= \vb{p}_0^{-} \rho_{ge} + \vb{p}_0^{+} \rho_{eg} \\ - &\equiv \vb{p}^{-}(t) + \vb{p}^{+}(t) + &\equiv \vb{p}^{-} + \vb{p}^{+} \end{aligned}$$ Where we have split $$\vb{p}$$ analogously to $$\vb{E}$$ @@ -117,8 +117,9 @@ Its equation of motion can then be found from the optical Bloch equations: $$\begin{aligned} \dv{\vb{p}^{+}}{t} - = \vb{p}_0^{+} \dv{\rho_{eg}}{t} - = - \vb{p}_0^{+} \Big( \gamma_\perp + i \omega_0 \Big) \rho_{eg} + &= \vb{p}_0^{+} \dv{\rho_{eg}}{t} + \\ + &= - \vb{p}_0^{+} \Big( \gamma_\perp + i \omega_0 \Big) \rho_{eg} + \frac{i}{\hbar} \vb{p}_0^{+} \Big( \vb{p}_0^{-} \cdot \vb{E}^{+} \Big) \Big( \rho_{gg} - \rho_{ee} \Big) \end{aligned}$$ @@ -147,7 +148,8 @@ we find its equation of motion to be: $$\begin{aligned} \dv{d}{t} &= \dv{\rho_{ee}}{t} - \dv{\rho_{gg}}{t} - = 2 \gamma_g \rho_{gg} - 2 \gamma_e \rho_{ee} + \\ + &= 2 \gamma_g \rho_{gg} - 2 \gamma_e \rho_{ee} + \frac{i 2}{\hbar} \Big( \vb{p}^{-} \cdot \vb{E}^{+} - \vb{p}^{+} \cdot \vb{E}^{-} \Big) \end{aligned}$$ |