1. The problem statement, all variables and given/known data I'm working through a step potential and I am confused as to why one of the coefficients doesn't go to zero. V(x) = 0 when x < 0; V(x) = V_not when x > 0; a. Calculate reflection coefficient when E < V_not I can solve the reflection part, it is a step towards it that i am confused about. 2. Relevant equations 3. The attempt at a solution Now i know the solutions solve to: Aexp(ikx)+Bexp(-ikx) where k= sqrt(2mE)/hbar when x<0 Cexp(lx) where l=sqrt(-2m(E-V_not)/hbar when x>0 So my question is why doesn't B=0? Because when x->-infinity it goes to infinity so B has to be 0. The only reason i can think it wouldn't is because of tunneling. If this is the case how do I spot this. Is it only relevant in step potentials?