Probability Flux for the Potential Step

The probability flux is given by

We can save some effort by noticing that this contains an expression minus its complex conjugate.
(This assures that term in brackets is imaginary and the flux is then real.)

For

The probability to be reflected is the reflected flux divided by the incident flux. In this case its easy to see that its as we said. For

The probability to be transmitted is the transmitted flux divided by the incident flux.

again as we had calculated earlier.

Jim Branson 2013-04-22