Scattering by a delta potential (source code)

= Scattering by a delta potential

For $V(x)=V_0\delta(x)$, $E=\hbar^2k^2/(2m)$, and $\gamma=mV_0/(\hbar^2k)$, continuity and the derivative jump give
$$
t=\frac1{1+i\gamma},
\qquad
r=\frac{-i\gamma}{1+i\gamma}.
$$
They obey $|r|^2+|t|^2=1$ and $r^*t+t^*r=0$.