EPW Forum

Dear EPW developers,
I am wondering whether the current implementation of EPW enables users to solve two-band (or even multi-band) isotropic Eliashberg equation.
So far if we provide a total "a2f" file, a "one-band" isotropic Eliashberg equation is solved (one Z and one Delta). Is it possible that we provide multiple "a2f" files (a2f_11, a2f_12, a2f_21, a2f_22) and a "two-band" isotropic Eliashberg equation is solved (two Z and two Delta)?
A closely related question is: can EPW calculate band-resolved "a2f"? A post on this forum says that if we fix "ibnd" and "jbnd" in eliashberg_setup.f90, then we can get band-resolved "a2f". But does that mean for a two-band system, we need to run epw four times in order to get "a2f_11", "a2f_12", "a2f_21" and "a2f_22"? Is there a convenient way to get band-resolved "a2f" from EPW?
Thank you very much.

Dr. Hanghui Chen
Department of Physics
NYU Shanghai and New York University

Hi,

At this point the code only works with a single-band in the isotropic case.

The code can calculate a2fij(ik,iq,ibnd,jbnd,iwph) but that specific subroutine is not used at this point. The subroutine is named evaluate_a2fij and can be found in superconductivity_aniso.f90

Best,
Roxana

Dear Roxana,
Thank you very much.

Dr. Hanghui Chen
NYU Shanghai and New York University