X-Git-Url: https://hackdaworld.org/gitweb/?a=blobdiff_plain;f=solid_state_physics%2Ftutorial%2F1_03s.tex;fp=solid_state_physics%2Ftutorial%2F1_03s.tex;h=1174731f4855a42f60e3e3ed2fdd34a42c01e304;hb=a7f0bd01ad41cd6b3508f30a4ff9b7cbb2f829c7;hp=0000000000000000000000000000000000000000;hpb=32f786010b14f1197f69bddc12e6e35bff697fba;p=lectures%2Flatex.git diff --git a/solid_state_physics/tutorial/1_03s.tex b/solid_state_physics/tutorial/1_03s.tex new file mode 100644 index 0000000..1174731 --- /dev/null +++ b/solid_state_physics/tutorial/1_03s.tex @@ -0,0 +1,71 @@ +\pdfoutput=0 +\documentclass[a4paper,11pt]{article} +\usepackage[activate]{pdfcprot} +\usepackage{verbatim} +\usepackage{a4} +\usepackage{a4wide} +\usepackage[german]{babel} +\usepackage[latin1]{inputenc} +\usepackage[T1]{fontenc} +\usepackage{amsmath} +\usepackage{ae} +\usepackage{aecompl} +\usepackage[dvips]{graphicx} +\graphicspath{{./img/}} +\usepackage{color} +\usepackage{pstricks} +\usepackage{pst-node} +\usepackage{rotating} + +\setlength{\headheight}{0mm} \setlength{\headsep}{0mm} +\setlength{\topskip}{-10mm} \setlength{\textwidth}{17cm} +\setlength{\oddsidemargin}{-10mm} +\setlength{\evensidemargin}{-10mm} \setlength{\topmargin}{-1cm} +\setlength{\textheight}{26cm} \setlength{\headsep}{0cm} + +\renewcommand{\labelenumi}{(\alph{enumi})} + +\begin{document} + +% header +\begin{center} + {\LARGE {\bf Materials Physics I}\\} + \vspace{8pt} + Prof. B. Stritzker\\ + WS 2007/08\\ + \vspace{8pt} + {\Large\bf Tutorial 2 - proposed solutions} +\end{center} + +\section{Drude theory of metallic conduction} +\begin{enumerate} + \item $U=IR \Rightarrow EL=jA\rho\frac{L}{A} + \Rightarrow E=j\rho$ + \item distance: $v\,dt$\\ + number of electrons crossing $A$: $n(v\,dt)A$\\ + $\Rightarrow$ $j=\frac{I}{A}=\frac{dQ/dt}{A}=\frac{-e\,n(v\,dt)A/dt}{A} + =-nev$ + \item \begin{itemize} + \item In the absence of an electric field, electrons are as likely + to be moving in any one direction as in any other. + The velocity averages to zero. + As expected, according to the above equation, there is no + net electric current density. + \item Since electrons emerge in a random direction + there will be no contribution from the thermal velocity + to the average electronic velocity. + \item $v_{average}=at=\frac{F}{m}\tau=-\frac{eE}{m}\tau$ + \end{itemize} + \item \begin{itemize} + \item $j=\left(\frac{ne^2\tau}{m}\right)E$\\ + \item $j=\sigma E \Rightarrow \sigma=\frac{ne^2\tau}{m}$ + \end{itemize} + \item Energy transfer: $\frac{m}{2}v_{drift}^2$, + $\qquad v_{drift}$: + end drift velocity of the accelerated electron\\ + $v_{drift} \ne v_{average}$ + + +\end{enumerate} + +\end{document}