Dear sir,
Could you please provide me an working example of this type?

Best Regards
Research Scholar
Department of Physics & Astrophysics
University of Delhi
New Delhi-110007

Hi again,

I f you want translational symmetry, you need to use wraparound module and you will need to find your result only on one unit cell.
You will have also to do integration on the Brillouin zone.

I hope this helps

On Thu, May 7, 2020 at 5:12 PM Naveen Yadav <naveengunwal72@gmail.com> wrote:
Dear sir,
I understand what you have said.  But how can I maintain translation symmetry ?because my system is 3D and for plotting current I access the sites of 3D system using list(sys.sites) and plot the current for 2D slice. Please suggest me.

Best Regards
Research Scholar
Department of Physics & Astrophysics
University of Delhi
New Delhi-110007

Dear Naveen,

What you get is what is expected. You do not have translational symmetry.
Rewrite your code by keeping only two dimensions and you will see why.

I hope this helps,

On Thu, May 7, 2020 at 12:52 PM Naveen Yadav <naveengunwal72@gmail.com> wrote:
Dear KWANT Developers,
I am trying to plot the current density. The procedure is straightforward. I have attached leads to the scattering region (leads have same onsite and hopping as of the scattering region) as
sys[(lat(z,y,x) for z in range(H) for y in range(W)for x in range(L))]=onsite
sys[kwant.builder.HoppingKind((1, 0, 0), lat, lat)] = hoppingz
sys[kwant.builder.HoppingKind((0, 1, 0), lat, lat)] = hoppingy
sys[kwant.builder.HoppingKind((0, 0, 1), lat, lat)] = hoppingx

lead[(lat(z,y,x)  for z in range(H) for y in range(W)for x in range(L))]=onsite
lead[kwant.builder.HoppingKind((1, 0, 0), lat, lat)] = hoppingz
lead[kwant.builder.HoppingKind((0, 1, 0), lat, lat)] = hoppingy
lead[kwant.builder.HoppingKind((0, 0, 1), lat, lat)] = hoppingx

As you can see from the plot there is a discontinuity in the plot at (W=20).  Why it is so even if the scattering region and leads have same onsite and hopping and there is translation symmetry throughout ?

--
Best Regards,