regarding to band structure

[arpit]

can any tell me what the band structure in the below image explain

[arpit]

sir i have one other question also...
i am generating a z-shape graphene ribbon...for that firstly i generate graphene nano-ribbon using custum-builder and then i translate the atoms to generate the structure(image attached below) and then generate the band structure of that distorted ribbon....while calculating bandstructure the default brillion zone route is (G,Z) and i am getting a flat bandstructure..i am attaching the image of that structure.....
so my question is that how i will calculate the correct bandstructure...and  what  must be brillion zone route

[arpit]

dear andres blom sir i am waiting for your response.....................

[ugglebot]

Your structure is not periodic along Z, so you can't expect to get any sensible results from a band structure calculation like that. In fact, it's not periodic in any direction at all, so it's like a molecule, so the result will be flat lines (molecular levels, sort of).

No offense my friend, but it would be a good idea if you study in a basic theory book what a band structure is. You need to understand the Brillouin zone concept, and the relation between the symmetry points like G,Z and the periodicity of the geometry.

[arpit]

thanks for your motivation,,,,but in some papers they use this type geometry and calculate band structure how is that possible...then?

[ugglebot]

Probably they don't use exactly this kind of geometry. For a band structure to make any sense, the structure needs to be periodic, there is no way around that

[arpit]

ok i understand ...but my another question is that
 can we plot the transmission spectrum of these type of structures directly and density of states also??

one more help
can you sugest me a good book for understanding band structures???

[Anders Blom]

The new ATK version (11.2) can compute the zero-bias transmission spectrum of a periodic system directly. The cell must fulfill the basic requirements for electrodes, however (periodic in Z, directed along Z, and long enough). The DOS can be obtained for any periodic system.

Regarding some basic text on band structure, my first instinct, as always, was to Google it, but it's actually not as easy as one might think... The best option is probably some standard textbook on solid state physics, like Ibach and Luth "Solid-State Physics" or Richard Martin's excellent book "Electronic Structure: Basic Theory and Practical Methods".

[arpit]

thank you sir....