X-Git-Url: https://hackdaworld.org/gitweb/?p=lectures%2Flatex.git;a=blobdiff_plain;f=solid_state_physics%2Ftutorial%2F1_06s.tex;h=7d551131e8178de8d97797bf43e5c7a758d257c4;hp=4e965e31368b9f3353ef8b25dc84beb491688101;hb=80df9b92f696a4b82e0cf46054c14efdfd8c1bce;hpb=6c4e0f74452033badf606ba05abc9c77b2331566 diff --git a/solid_state_physics/tutorial/1_06s.tex b/solid_state_physics/tutorial/1_06s.tex index 4e965e3..7d55113 100644 --- a/solid_state_physics/tutorial/1_06s.tex +++ b/solid_state_physics/tutorial/1_06s.tex @@ -16,6 +16,8 @@ \usepackage{pstricks} \usepackage{pst-node} \usepackage{rotating} +\usepackage{epic} +\usepackage{eepic} \setlength{\headheight}{0mm} \setlength{\headsep}{0mm} \setlength{\topskip}{-10mm} \setlength{\textwidth}{17cm} @@ -66,13 +68,34 @@ \end{itemize} \end{enumerate} -\section{\ldots} - -\ldots +\section{Dielectric function of the free electron gas} \begin{enumerate} - \item \ldots - \item \ldots + \item \begin{itemize} + \item Equation of motion: $m\frac{d^2x}{dt^2}=-eE$ + \item Ansatz: $x(t)=x_0 e^{-i\omega t}$ + \item Solution of the equation of motion: $-m\omega^2x=-eE$ + \item Dipole moment: $p=-ex=\frac{-e^2E}{m\omega^2}$ + \item Polarization: $P=np=\frac{-ne^2E}{m\omega^2}$ + \item Dielectric function: + $\epsilon(\omega)=1+\frac{P}{\epsilon_0E} + =1+\frac{-ne^2E}{m\omega^2\epsilon_0E} + =1-\frac{ne^2}{\epsilon_0m\omega^2}$ + \end{itemize} + \item \begin{itemize} + \item Using $\omega_p^2=\frac{ne^2}{\epsilon_0m}$\\ + $\Rightarrow \epsilon(\omega)=1-\frac{\omega_p^2}{\omega^2}$ + \item Sketch of dielectric function:\\ + (page 2) + \item Influence on electromagnetic waves:\\ + $\frac{\omega}{\omega_p}>1\Leftrightarrow \omega>\omega_p$: + $\Rightarrow \epsilon=n^2>0$ + $\Rightarrow$ transparent region\\ + $\frac{\omega}{\omega_p}<1\Leftrightarrow \omega<\omega_p$: + $\Rightarrow \epsilon=n^2<0$ + $\Rightarrow$ reflective region\\ + \end{itemize} +\input{dielectric_pslatex} \end{enumerate} \end{document}