%\includegraphics{excs/qm1_blatt04_SS08.pdf} %\pagebreak \chapter{Quantenmechanik I - Übungsblatt 4} \section{Aufgabe 9: Zeitentwicklung eines allgemeinen Zweizustandssystems} \begin{math} H = \hbar \inlinematrix{A & B \\ B & -A} \\ A = \Omega \cosb{2 \theta} \\ B = \Omega \sinb{2 \theta} \\ E_\pm = \pm \hbar \Omega \end{math} \subsection*{a)} \begin{align} \ket{\chi_+} &= \inlinematrix{\sinb{2 \theta} \\ 1 - \cosb{2 \theta}} &= \inlinematrix{\cosb{\theta} \\ \sinb{\theta}} \\ \ket{\chi_-} &= &= \inlinematrix{\sinb{\theta} \\ -\cosb{\theta}} \end{align} \subsection*{b)} \begin{align} \i \hbar \diffPs{t} \ket{\psi} &= H \ket{\psi} \\ \ket{\dot{\psi}} &= -\i \Omega \inlinematrix{\cosb{2 \theta} & \sinb{2 \theta} \\ \sinb{2 \theta} & -\cosb{2 \theta}} \ket{\psi} \\ \ket{\psi(t)} &= c_1 \cdot e^{\i \Omega t} \ket{\chi+} + c_2 \cdot e^{-\i \Omega t} \ket{\chi-} \\ \ket{\psi(0)} &= \inlinematrix{\lambda \\ \mu} \\ \inlinematrix{c_+(t) \\ c_-(t)} &= \sbk{\lambda \cosb{\theta} + \mu \sinb{\theta}} \cdot \inlinematrix{\cosb{\theta} \\ \sinb{\theta}} \cdot e^{-\i t} + \sbk{\lambda \sinb{\theta} - \mu \cosb{\theta}} \cdot \inlinematrix{\sinb{\theta} \\ -\cosb{\theta}} \cdot e^{\i \Omega t} \end{align} \subsection*{c)} %hier stimmt evtl. was nicht \begin{align} \ket{\psi(0)} &= \inlinematrix{0 \\ 1} \\ \abs{\braket{+}{\psi(t)}}^2 &= \sin^2\sbk{\Omega t} \cdot \sin^2\sbk{2 \theta} \\ \abs{\braket{-}{\psi(t)}}^2 &= \cos^2\sbk{\Omega t} + \sin^2\sbk{\Omega t} \cdot \cos^2\sbk{2 \Omega} \end{align} \section{Aufgabe 10: Zerfall eines instabilen Zustandes} \subsection*{a)} \subsection*{b)} \subsection*{c)} \subsection*{d)} \subsection*{e)} \subsection*{f)}