Question

The tight binding energy dispersion (E-k) relation for electrons in a one-dimensional array of atoms having lattice constant 'a' and total length 'L' is :
E=E0−β−2γcoska
Where E0,β and γ are constants and k is the wave vector.
The density of states of electrons (including spin degeneracy) in the band is given by
a) Lπγasin(ka)
b) L2πγasin(ka)
c) L2πγacos(ka)
d) Lπγacos(ka)

Answer 1

The density of states of electrons (including spin degeneracy) in the band is given by

$$L^2πγa\cos(ka)$$