The approximation for Debye-Waller selfenergy

[Fawei]

Dear developers/users,
I am studying the Fermi surface at low and high temperature renormalized by electron-phonon interactions.
From the tutorial, I find that EPW code compute the Fan-Migdal selfenergy, while the Debye-Waller selfenergy is approximately included by using a sum rule to conserve the electron number. I am wandering, does this approximation fix the Fermi surface, so that the Fermi surface would not change at different temperatures?

Best
Fawei

[sponce]

Dear Fawei,

This does not fix the Fermi surface. We simply made a constrain at the Fermi level (wherever it is).

Best,
Samuel

[Fawei]

Dear Samuel,
That's great, so that I can use the EPW code in Fermi surface study. Thanks for your kind reply!
Best,
Fawei