Let's consider a particle propagating towards a step of potential energy region i region ii the problem can be divided in two regions in region , the particle can only have an energy e0, so its wavefunction will have the form (z) = a, exp(ik, z) + b, exp(-ik, x) with k0 in region li, two cases can occur: a) e > vo which will make the wavefunction have the form ψ11 ( )-all exp(ik11x + b11 exp㈠k11z with k 1 2 e v b) e < vo, which will make the wavefunction have the form ψ11(z) = all exp(allz) + b11 exp(-k11z), with k, = considering the particle propagating from left to right (case a) and the wavefunction to be defined when x-+oo in case b, all-0 the functions from both regions will connect at 0 and need to be continuous (value and first derivative) wi 2m(vo-e) the first relation gives a1 + bl b11 the second relation gives k1 (al-b)-k11 b11 for case a ikr(ai - bi)kii forcase b considering al = 1 as a reference, we obtain kt- kit 2kr k+ki 2m. e 2m(e-w.) 2k12) and ψ11 (x) = kii-ikr kti tik 11 (z) = kl7t 167 expl-kliz) with k, 21,2-and