Why Is the Radius of a Fermi Sphere Given by \( k_F = (3 \pi^2 n)^{1/3} \)?

[ehrenfest]

[SOLVED] radius of the fermi sphere

Homework Statement

On page 249 of ISSP, Kittel says that the radius of a free electron Fermi sphere is

$$k_F = \left(3 \pi^2 n \right)^{1/3}$$

where n is the concentration of electrons.

I don't know why that is true.

EDIT: never mind; they derive that on page 138

Homework Equations

The Attempt at a Solution

 

[MeChaState]

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