Reflection probability from potential well

$TextStyle = {FontFamily -> Times, 
        FontSize -> 14}
<< Graphics`Graphics`

{hbar, m, a} = {1, 1, 1}
V0 = 2
k[E_] := Sqrt[2  m*E/hbar^2]
q[E_] := Sqrt[2  m (E + V0)/hbar^2]
R[E_] := (q[E]^2 - k[E]^2) 
        Sin[2  q[E] 
              a]
/(2  k[E] q[E] 
                Cos[2  q[E] a]
 - 
              I (q[E]^2 + k[E]^2) 
                Sin[2  q[E] a])
\(p1 = 
      LogPlot[Abs[R[E]]^2, {E, 0, 
          25}, 
PlotRange -> {{0, 25}, {0.0001, 
              1}}, 
AxesLabel -> {"E", "P"}, 
PlotLabel -> "Reflection probability"]\)

Transmission probability from potential barrier

{hbar, m, a} = {1, 1, 1}
V0 = 10   
k[E_] := Sqrt[2  m*E/hbar^2]
q[E_] := Sqrt[2  m (E - V0)/hbar^2]
T[E_] := 
      2  k[E] q[
            E]
/(2  k[E] q[E] 
                Cos[2  q[E] a]
 - 
              I (q[E]^2 + k[E]^2) 
                Sin[2  q[E] a])
\(p2 = 
      Plot[Abs[T[V0*x]]^2, {x, 0, 
          4}, 
PlotRange -> {{0, 4}, {0, 
              1.1}}, 
AxesLabel -> {"E/V0", "P"}, 
PlotLabel -> "Transmission probability"]\)