[Wannier] Is the berry curvature printed in Wannier gauge in postw90?

[Vahid Askarpour]

Dear Wannier90 Community,


The berry curvature is printed in kpath.f90 by

> call berry_get_imf_klist(kpt,imf_k_list)
> curv(loop_kpt,1)=sum(imf_k_list(:,1,1))
> curv(loop_kpt,2)=sum(imf_k_list(:,2,1))
> curv(loop_kpt,3)=sum(imf_k_list(:,3,1))
> 
> and later
> 
> curv=-curv
> do loop_kpt=1,total_pts
>      write(dataunit,’(4E16.8)') xval(loop_kpt), curv(loop_kpt,:)
>  enddo

In the berry_get_imf_klist subroutine of berry.f90, it says

> ! Gather W-gauge matrix objects
> call wham_get_eig_UU_HH_JJlist(kpt,eig,UU,mdum,JJp_list,JJm_list)
> 
> For example, the third component of imf_k_list is
> 
> mdum=matmul(JJm_list(:,:,if,alpha_A(i)),JJp_list(:,:,if,beta_A(i)))
> imf_k_list(3,i,if)=-2.0_dp*utility_im_tr(mdum)
> 
JJm_list and JJp_list are in W-gauge. So imf_k_list is in W-gauge. Consequently, is curv(loop_kpt:)  in W-gauge?

I would appreciate any hints on what I might be missing here.

Thanks,
Vahid

Vahid Askarpour
Department of Physics and Atmospheric Science
Dalhousie University
Halifax, Nova Scotia
CANADA