Understanding Quantum Wavepackets: Propagation and Reflection Examples
Explore free particle eigenstates, scattering states, and wavepacket normalization. Calculate wavefunction evolution and momentum expectation values for various scenarios. Visualize wavepacket reflections and animations for deeper understanding.
Understanding Quantum Wavepackets: Propagation and Reflection Examples
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Presentation Transcript
Plane wave eigenstates: Free particle x Wavepackets etc. • scattering states • non-normalizable • continuous spectra
Linear superpositions of plane wave solutions with Normalization: Wavepackets
Example 1 Unfortunately, the integrand is badly behaved and difficult to evaluate even numerically.
is a free particle propagator “imaginary time” Propagator
Calculate evolution of the wavefunction using the propagator
Calculate the momentum expectation value: Example 3: moving Gaussian wavepacket How do we know this is a moving wavepacket?
Boundary condition: Eigenstates: 0 0 x Propagator: Example 4: wavepacket reflected from a hard wall
For very nice and instructive animations visit http://www.quantum-physics.polytechnique.fr/en/pages/p0103.html Wavepackets reflected from steps & barriers