\hbar}\sqrt{2m(E+V_0)}x},~0<x<a,\\ 
=C_{+}e^{i{1 \over \hbar}\sqrt{2mE}x},~a<x,
\end{cases}\end{aligned}$$ where at $x<0$, a right-moving plane wave comes in and a reflected left-moving wave of magnitude $B_{-}$ is reflected, and at $x>a$, a right-moving wave of magnitude $C_{+}$ is refracted. Coefficients $A_i$ show the magnitude in the inside of potential, $0<x<a$. These coefficients are found as [@Landau] $$\begin{aligned}
& &A_{+}=2{1+\sqrt{1+V_0/E} \over (1+\sqrt{1+V_0/E})^2-(1-\sqrt{1+V_0/E})^2 e^{2{i\over \hbar}\sqrt{2m(E+V_0)} a}},\\
& &A_{-}=2{(-1+\sqrt{1+V_0/E})e^{2{i \over \hbar}\sqrt{2m(E+V_0)}a} \over (1+\sqrt{1+V_0/E})^2-(1-\sqrt{1+V_0/E})^2 e^{2{i\over \hbar}\sqrt{2m(E+V_0)} a}},\end{aligned}$$ and coefficients $B_{-},C_{+}$ are found as $$\begin{aligned}
B_{-}&=&1-2{{\sqrt{1+V_0/E}+1+V_0/E+(\sqrt{1+V_0/E}-1-V_0/E)}e^{2{i\over \hbar}\sqrt{2m(E+V_0)} a} \over (1+\sqrt{1+V_0/E})^2-(1-\sqrt{1+V_0/E})^2 
e^{2{i\over \hbar}\sqrt{2m(E+V_0)} a}},\nonumber\\
\\
C_{+}&=&2{(1+\sqrt{1+V_0/E}) +(-1+\sqrt{1+V_0/E})e^{{i \over \hbar}\sqrt{2m(E+V_0)}a} \over (1+\sqrt{1+V_0/E})^2-(1-\sqrt{1+V_0/E})^2 e^{2{i\over \hbar}\sqrt{2m(E+V_0)} a}}\nonumber\\
&\times& e^{{i\over \hbar}(\sqrt{2m(E+V_0)}a-\sqrt{2mE}a)}. \end{aligned}$$ Wave packets at $x>0$ and $x<0$ are computed as $$\begin{aligned}
\psi_{wp}^{1}&=&\int dk ~N(k) e^{i(kx-\frac{Et}{\hbar})},~x\ll0, \\
\psi_{wp}^{2}&=&\int dk ~N(k) B_{-}(k)e^{-i(kx + \frac{Et}{\hbar})},~x\ll 0, \\
\psi_{wp}^{3}&=&\int dk ~N(k) C_{+}(k) e^{i(kx - \frac{Et}{\hbar})},~x\gg 0,\end{aligned}$$ where $N(k)$ is given in Eq. $(\ref{normalization})$.

Wave packets $\psi_{wp}^{i}(i=1 - 3) $ are computed numerically. In the negative $x$ region, the minimum wave packet comes in, and refracted and reflected wave packets are generated. The variances of $\psi_{wp}^1$, $\psi_{wp}^2$, and $\psi_{wp}^3$ are computed numerically and are given by $$\begin{aligned}
& &\delta x^1 \times \delta p^1 = \frac{\hbar}{2},\\
& &\delta x^2  \times \delta p^2 = (1.0 \sim 1.6)\times \frac{\hbar}{2},\\
& &\delta 