[Pw_forum] honeycomb lattices and shift in gamma point?

[Michael Mehl]

Dev,

I believe that if you look closely at the published band structures of 
graphene you'll find that many graphs are <em>centered</em> on the K 
point.  This doesn't mean that the K point is now the origin, it just 
means that the K point is the center of the published graph.  That's 
because K is the interesting part of the band structure.

A quick Google (TM) of the web reveals more about graphene than I really 
wanted to know tonight.  Here's a useful tutorial:

http://www.ph.utexas.edu/~macdgrp/meetings/hongki-graphene(partial).pdf

Note particularly the band structure on page 8, and compare it to the 
band structure on page 19.


harman dev wrote:
> Dear all,
> 
>     This is short extension with reference to my previous message. I
> was wondering if this shift in the origin of the Brillouin Zone for
> graphene is associated with the honeycomb symmetry. As mentioned, a
> hcp cell such as that of Mg has the gamma point as the origin of its
> Brillouin Zone whilst the point K seems to be the origin of the
> Brillouin Zone for honeycomb lattices such as graphene and boron
> nitride. Any comments on this would be great appreciated. Thank you.
> 
> Cheers,
> Dev
> 


-- 
					Mike Mehl
					Naval Research Laboratory
					Washington DC USA