1. The problem statement, all variables and given/known data There is a step barrier at x=0, V_0 > E I am given: ψi = e^i(kx−ωt) ---> ψr = R e^i(−kx−ωt) <--- ψt = T e^(−αx−iωt) ---> Part of question I am confused about: State the two boundary conditions satisﬁed by the wave function at x = 0 and hence find expressions for |R|^2 and |T|^2 2. Relevant equations N/A 3. The attempt at a solution I have already worked out an equation for alpha in the previous part. ψ1 = ψi + ψr ψ2 = ψt I started to apply the conditions ψ1(0) = ψ2(0) to get 1 + R = T and d/dx ψ1(0) = d/dx ψ2(0) to get ik - iRk = -αT I solved the above to get R = (ik +αT) / ik with T = 1 + R etc I understand that |R|^2 = R x R* and |T|^2 = T x T* However I am told that T = 1 - R since these are probability coefficients. Do I solve with T = 1-R (probability coefficients) or T = 1+R (using ψ1(0) = ψ2(0))? I am confused which one to use and why. Many thanks.