The Nature of the Cooper Pair - University of Liverpool

So in energy variable, the density of states is
g(ε) = g(k) dk
dε
At the Fermi energy,
= R
π .me
2k .
g(0) = meR
.
2πkF Note that we are taking the Fermi energy at the origin, so zero
energy here means Fermi energy. Combining these ideas, we
obtain
�
k ′
a k ′V kk ′ ≈
�
a ε ′V εε ′g(0)dε ′
The lower limit of the integral is 0, the Fermi level. To find the
upper limit, we recall that V kk ′ is zero if k − k ′ > ω D/ve.
Superconductivity 42