EPW Forum

Dear developers,

I have a doubt regarding the impurity scattering implementation and its validity for 2D materials/systems.

As I see from the code, the matrix elements for such transitions are computed by "rgd_imp_epw_fine" within "rigid_epw.f90" using a bare 3D Coulomb potential, namely "(4*pi*Z*e^2)/(eps_inf*q^2)*U_{n,k}*U_{m,k+q}". Threrefore, I guess that it is not valid for 2D materials as electrostatics differs. Is that the case? If so, for it to be valid for 2D materials, would it be as easy as to do like in "rgd_blk" and similar subroutines (i.e. the 2D electrostatics IF clauses)?

Best regards,

Martí Raya Moreno

I have also been trying to compute charged impurity scattering rates for 2D materials and am getting scattering times on the order of microseconds instead of picoseconds. I am unsure as to why the results are so different, is it because the formalism given in the documentation is only compatible with 3D systems?

Does a newer version of EPW provide a way to compute charged impurity scattering for 2D materials? Any help would be appreciated.