4 Tunnelling: wave packets and stationary states
One of the most surprising aspects of quantum physics is the ability of particles to pass through regions that they are classically forbidden from entering. This is the phenomenon of quantum-mechanical tunnelling that was mentioned in Session 1.
In Session 4 we first demonstrate the phenomenon of tunnelling with the aid of wave packets. We then go on to examine some of its quantitative features using stationary-state methods, similar to those used in our earlier discussion of scattering from wells and barriers.