Transmission Spectrum of Graphene-Nickel Interface

[monir_apece]

I was trying to reproduce transmission spectrum from Kurt Stokbro et.al.  I tried to optimize the structure geometry first then simulated for 401 k-point sampling.  Exchange correlation LSDA and FFT as Poisson solver were used. But the thing was that transmission spectrum was not the same as the paper. Please help me on this topic.

[Umberto Martinez]

The reason could be because in the paper an extended basis set for Nickel has been used to get a better description of the Ni work function.
see basis set attached

[monir_apece]

I am new with ATK and I dont know how to use  scripting very well. I would appreciate your answer through GUI format or tell me how to use extended basis set in my code. Thank you

[kstokbro]

In the gui you will need to save the script with script detail set to default. In this case you will get all the details out of the basis set. You can now change the details of the basis set in the script.

I attach the input files and scripts from the paper

[monir_apece]

I was trying to follow the tutorial available in the website to grow graphene sheet (http://quantumwise.com/publications/tutorials/item/102-graphene-nickel-interface). By default it was giving me Armchair Graphene sheet using GUI. Is it possible to build Zigzag graphene sheet using GUI?

[Umberto Martinez]

I guess you mean zig-zag nanoribbon.
In this case, from the builder, use the add>from plugin>nanoribbon plugin whre you can select the zigzag or the armchair geometry.

[monir_apece]

Dear Mr. Umberto Martinez,

Thank you. Actually I was talking on how can I build zigzag edge graphene. Because by default the builder was giving me Armchair edge graphene only.

[Umberto Martinez]

ok, in this case, after you have created the Ni/Graphene interface as reported in the tutorial, simply repeat in A direction instead of B as done there.
All the other steps are basically the same.
Just be careful at step number 5 where you have to swap axis  to have C/Z along the transport direction.

[monir_apece]

Dear Umberto Martinez,

Thank you. I tried the last configuration from the journal paper (from the figure-d section). I found out that whenever I am selecting C/Z (where the structure is periodic) as the width of the structure and transport direction, I couldn't convert the structure from bulk to device. I could do it when selecting B as the width and transport direction. Please help me if I can choose B as the transmission direction and how?

[Umberto Martinez]

Hard to understand and "see" it from here.
Can you please attach you bulk structure. Just at the step before the device conversion.
You may have created a different interface from the one in the tutorial and now we are confusing A,  and C

[monir_apece]

Dear Mr. Umberto Martinez,

Please have a look.

[Umberto Martinez]

These configurations correspond to the structure reported in Fig.1a of your reference.
And you can create a device from your "Graphene_Nickel_Interface_1a_after swap.py" structure.

In order to get the structure in Fig. 1d you have to repeat along B (if A was the one that gave you the attached structures) RIGHT AFTER the creation of the interface step.

Finally, delete the C and Ni atoms with the select by expression tool and you will be able to create a device.