diff options
Diffstat (limited to 'source/know/concept/electric-dipole-approximation')
| -rw-r--r-- | source/know/concept/electric-dipole-approximation/index.md | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/source/know/concept/electric-dipole-approximation/index.md b/source/know/concept/electric-dipole-approximation/index.md index 7c710ec..35cf00c 100644 --- a/source/know/concept/electric-dipole-approximation/index.md +++ b/source/know/concept/electric-dipole-approximation/index.md @@ -30,6 +30,8 @@ so that $$\vb{A} \cdot \vu{P} = \vu{P} \cdot \vb{A}$$: $$\begin{aligned} \comm{\vb{A}}{\vu{P}} \psi + &= (\vb{A} \cdot \vu{P} - \vu{P} \cdot \vb{A}) \psi + \\ &= -i \hbar \vb{A} \cdot (\nabla \psi) + i \hbar \nabla \cdot (\vb{A} \psi) \\ &= i \hbar (\nabla \cdot \vb{A}) \psi @@ -75,7 +77,7 @@ $$\begin{aligned} Where $$\vb{E}_0 = \omega \vb{A}_0$$. Let us restrict ourselves to visible light, whose wavelength $$2 \pi / |\vb{k}| \sim 10^{-6} \:\mathrm{m}$$. -Meanwhile, an atomic orbital is several Bohr $$\sim 10^{-10} \:\mathrm{m}$$, +Meanwhile, an atomic orbital is several Bohr radii $$\sim 10^{-10} \:\mathrm{m}$$, so $$\vb{k} \cdot \vb{x}$$ is negligible: $$\begin{aligned} |