Physical Significance
The phase modulation of the Bloch state is the same as that of a free particle with momentum, i.e. gives the state's periodicity, which is not the same as that of the lattice. This modulation contributes to the kinetic energy of the particle (whereas the modulation is entirely responsible for the kinetic energy of a free particle).
In regions where the band is approximately parabolic the crystal momentum is equal to the momentum of a free particle with momentum if we assign the particle an effective mass that's related to the curvature of the parabola.
Read more about this topic: Crystal Momentum
Famous quotes containing the words physical and/or significance:
“It seems to be a law of nature that no man, unless he has some obvious physical deformity, ever is loth to sit for his portrait.”
—Max Beerbohm (1872–1956)
“For a parent, it’s hard to recognize the significance of your work when you’re immersed in the mundane details. Few of us, as we run the bath water or spread the peanut butter on the bread, proclaim proudly, “I’m making my contribution to the future of the planet.” But with the exception of global hunger, few jobs in the world of paychecks and promotions compare in significance to the job of parent.”
—Joyce Maynard (20th century)