Wavepackets etc. Plane wave eigenstates: scattering states non-normalizable continuous spectra x Free particle
Wavepackets withNormalization: Linear superpositions of plane wave solutions
Example 1 Unfortunately, the integrand is badly behaved and difficult to evaluate even numerically.
Propagator is a free particle propagator “imaginary time”
Calculate evolution of the wavefunction using the propagator
Example 2: Gaussian wavepacket
Example 3: moving Gaussian wavepacket How do we know this is a moving wavepacket? Calculate the momentum expectation value:
Example 4: wavepacket reflected from a hard wall Boundary condition: Eigenstates: Propagator: 0 x0
Wavepackets reflected from steps & barriers For very nice and instructive animations visit