Propagation of a free wavepacket

This simulation shows the spreading of a wavepacket, a phenomenon which is a direct consequence of the Heisenberg incertainty principle : If the wavepacket is well localized in configuration space, it must have a large width in momentum space. The parts of the wavepacket corresponding to a larger momentum will propagate faster, hence the spreading. This can be directly by directly looking at the real part of the wavefunction instead of the probability density. Indeed, the real part of the wavefunction shows the de Broglie wavelength, inversely proportional to the momentum. It can be observed that the smaller wavelengths move ahead of the larger wavelengths, resulting in the spreading of the wavepacket.