Hi Sergio,
This function appears to have scaling issues. If you plot
figure(1)
fplot(real(Z), [-2*h, 2*h])
figure(21)
fplot(imag(Z), [-2*h, 2*h])
you can see the function. I believe this addresses the question, but there are other things going on too. Possibly you were using E=1 just for test purposes, but compared to that value, 2*g^2 is infinitesimal. Also the function itself is an increasing exponential which is not good for a wave function unless there is some kind of hard boundary.
