# Solid state physics

1. Jan 25, 2008

### paullondon

Good evening ,

I will resolve a small problem but I don't know how I can do,

In l approximation of the strong coupling, the strucure of band of the electrons in a certain crystal is given by: E(k)=-[E1*cos(kx.a)+E2*cos(ky.b)+E3*cos(kz.c) ] Show that for a band very little filled, the electronic specific heat of electronic gas in this crystal is equivalent to the electronic specific heat such calculated for free electrons but with an effective mass m*=|detM|1/3 or M is the tensor of effective mass at least evaluated band is [ M-1 ]ij=(1/h²)*(d²E(k))/(dki dkj)