Question

Discuss the reduced zone, extended zone and periodic zones scheme ofE-k representation.

Answer 1

E-k representation

Explanation:

Due to the complexity of energy levels or energy bands in expressions such as Ek = h²k² / 2m, it is described in 3 different schemes.

1. The representation Ek = Ek + G shows all energy levels in all regions of the wavevector space. It is called the periodic zone scheme.
2. The representation Ek = h²k² / 2m shows all bands in the first Brillouin zone only. It is called the reduced zone scheme.
3. There extended zone scheme shows different bands in different Brillouin zones with discontinuities at zone edges.