Question

The effective mass of electrons in the band is given by

ℏ2/γa2cos(ka)


ℏ2/2γa2cos(ka)


ℏ2/γa2sin(ka)


ℏ2/2γa2sin(ka)

Answer 1

The effective mass of electrons in the band is given by

$$m^*=\frac{ℏ^2}{2γa^2\cos(ka)}$$