% Gleichung
\newcommand{\be}{\begin{equation}}
\newcommand{\ee}{\end{equation}}
% Mehrere Gleichungen, keine Numerierung
\newcommand{\ba}{\begin{eqnarray}}
\newcommand{\ea}{\nonumber\end{eqnarray}}
% Liste
\newcommand{\bi}{\begin{itemize}}
\newcommand{\ei}{\end{itemize}}
% ket-Zustand
\newcommand{\ket}[1]{
| #1 \rangle
}
% bra-Zustand
\newcommand{\bra}[1]{
\langle #1 |
}
% bra-ket
\newcommand{\braket}[2]{
\langle #1 | #2 \rangle
}
% Fette Symbole
\newcommand{\ff}[1]{
{\boldsymbol #1}
}
% cal
\newcommand{\ca}[1]{
{\cal #1}
}
% spur
\newcommand{\tr}{
\, \mbox{Sp} \:
}
% 2x2-Matrix
\newcommand{\mtt}[4]{
\left( 
\begin{array}{cc}
#1 & #2 \\ #3 & #4 \\
\end{array}
\right)
}
% 2-Vektor
\newcommand{\vtt}[2]{
\left( 
\begin{array}{cc}
#1 \\ #2 \\
\end{array}
\right)
}
% 3-Vektor
\newcommand{\vttt}[3]{
\left( 
\begin{array}{ccc}
#1 \\ #2 \\ #3 \\
\end{array}
\right)
}
% partielle Ableitung
\newcommand{\dn}[1]{
\frac{\partial}{\partial #1}
}
% partielle Ableitung
\newcommand{\dd}[2]{
\frac{\partial #1}{\partial #2}
}
