From 005f58500f06467a7e1863e620215bc4a7b0dde8 Mon Sep 17 00:00:00 2001 From: Daniel Bahrdt Date: Wed, 25 Jun 2008 12:22:45 +0200 Subject: [PATCH] =?UTF-8?q?=C3=BCbungsblatt=207=20aa18=20geschrieben?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ueb7.tex | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 60 insertions(+), 5 deletions(-) diff --git a/ueb7.tex b/ueb7.tex index 36e1e9f..2bf8419 100644 --- a/ueb7.tex +++ b/ueb7.tex @@ -1,15 +1,70 @@ -%\includegraphics{excs/qm1_blatt05_SS08.pdf} +%\includegraphics{excs/qm1_blatt07_SS08.pdf} %\pagebreak -\chapter{Quantenmechanik I - Übungsblatt 5} -\section{Aufgabe 11: Spin-1-Teilchen im konstanten Magnetfeld} +\chapter{Quantenmechanik I - Übungsblatt 7} +\section{Aufgabe 17: Unendlich hoher Potentialtop (Ergänzungen)} \subsection*{a)} \subsection*{b)} \subsection*{c)} -\section{Aufgabe 12: Das Ethen-Molekül} +\section{Aufgabe 18: Tunneleffekt} +\includegraphics{grafiken/U_A18_1.pdf} +\subsection*{a)} -\section{Aufgabe 13: Das Benzol-Molekül} +I +\begin{math} + -\frac{\hbar^2}{2m} \diffPs{x}^2 \Phi(x) = E \Phi(x) \\ + \Phi(x) =A e^{\i k x} + B e^{-\i k x} \\ + k = \sqrt{\frac{2 E M}{\hbar^2}} +\end{math} + +II $E < V_0$ +\begin{math} + \Phi(x) = C e^a + D e^{-qx} \\ % ist das nen q hier? + q = \sqrt{\frac{-2m(E-V_0)}{\hbar^2}} +\end{math} + +III +\begin{math} + \Phi(x) = \tilde{E} e^{\i k x} + F e^{-\i k x} +\end{math} + +\subsection*{b)} +\begin{math} + F = 0 + \Phi_I(0) = \Phi_{II}(0) \\ + A+B = C+D \\ + \diffT{x} \Phi_I(0) = \diffT{x} \Phi_{II}(0) \\ % anschlussbedingungen korrekt + \i k A - \i k B = q C - q D \\ + \inlinematrix{1 & 1 \\\i k & -\i k} \inlinematrix{A & B} = \inlinematrix{1 & 1 \\ q & -q} \inlinematrix{C & D} \\ + \Phi_{II}(a) = \Phi_{III}(a) \\ + C e^{a \cdot a} + D e^{-a \cdot a} = \tilde{E} e^{\i k a} \\ + \diffT{x} \Phi_{II}(a) = \diffT{x} \Phi_{III}(a) \\ + q C e^{a \cdot a} - q D e^{-a \cdot a} = \i k \tilde{E} e^{\i k a} \ + \inlinematrix{e^{a \cdot a} & e^{-a \cdot a} \\ q e^{a \cdot a} & q e^{-a \cdot a}} \inlinematrix{C & D} = \inlinematrix{\tilde{E} e^{\i k a} \\ \i k \tilde{E} e^{\i k a}} +\end{math} + +mit den Inversen von: (1) und (2) % geschweifte klammern unter matrix 1 und 2 setzen + +\begin{math} + %mit maxima berechnet + \inlinematrix{C & D} = \inlinematrix{\frac{{e}^{{a}^{2}}}{{e}^{2 {a}^{2}}-1} & -\frac{1}{\left( {e}^{3\,{a}^{2}}-{e}^{{a}^{2}}\right) q} \\ -\frac{{e}^{{a}^{2}}}{{e}^{2{a}^{2}}-1} & \frac{{e}^{{a}^{2}}}{\left( {e}^{2 {a}^{2}}-1\right) q}} \inlinematrix{\tilde{E} e^{\i k a} \\ \i k \tilde{E} e^{\i k a}} \\ + \inlinematrix{A & B} = \inlinematrix{\frac{1}{2} & -\frac{\i}{2k}\\ \frac{1}{2} & \frac{\i}{2k}} \inlinematrix{1 & 1 \\ q & -q} \inlinematrix{C & D} +\end{math} + +$\inlinematrix{C & D}$ eingesetzt ergibt: +\begin{align} + \tilde{E} &= \frac{2 k a}{e^{ika} \bbracket{(q^2 - k^2) \cdot \i sinh(q \cdot a) - 2 k q cosh(qa)} \\ + A &= 1 \\ + T &= \bbracket{\frac{E}{A}}^2 \\ + R &= 1 - T &= \bbracket{\frac{B}{A}}^2 \\ + T &= \frac{1}{\bbracket{\frac{a^2 - k^2}{2 q k}} \cdot 2 sinh^2(q a) + cosh^2(q a)} +\end{align} + + +\subsection*{c)} + +\section{Aufgabe 19: Doppeltes \delta-Potential} \subsection*{a)} \subsection*{b)} \subsection*{c)}