Question

Explain how the bloch theorem leads to the introduction of band theory

Answer 1

Answer:

Bloch theorem

Bloch theorem

A theorem that specifies the form of the wave functions that characterize electron energy levels in a periodic crystal. Electrons that move in a constant potential, that is, a potential independent of the position r , have wave functions that are plane waves, having the form exp(i k · r ). Here, k is the wave vector, which can assume any value, and describes an electron having momentum ℏ k . (The quantity ℏ is Planck's constant divided by 2&pgr;.) Electrons in a crystal experience a potential that has the periodicity of the crystal lattice. See Band theory of solids