EQUIVWAV

Animation of Equivalent Lattice Waves

This animation shows two equivalent lattice waves, one inside the first Brillouin zone and the other outside.

The wave number for the wave inside the first Brillouin zone is k=pi/4a (wavelength=8a, moving in +x direction).

The wave number for the wave outside the first Brillouin zone is k=pi/4a-2pi/a=-7pi/4a (wavelength=8a/7, moving in -x direction).