Michael Fuhrer's 'Science Snippet': Secret Lives of Electrons in Atomically-thin Materials

[@kleinpoe]

Wow that was a great introduction

[@Orientaliszt]

Since graphene is polycrystalline by nature, assuming a perfect graphene crystals connected by pentagons and heptagons randomly distributed in their edges, what will be the dispersion relation of such material?

[@yannickkamta2719]

i think you have to simulate that one, are u working on graphene edge properties?

[@SBLP24]

Actually if you add pentagons and heptagons you dont have a graphene but a deformed structure. This happens because only pure hexagons sp2 carbons resembles to a flat sheet of graphene. Aa different configuration will add an stress to the structure and get a bending out of plane. Look at C60, there you have pentagons... if you crunch the numbers you realize that hexagons are the way to go for many reasons... planar sp2 hibridization is just one of them. Another problem you are gonna encounter is that if you dont ahve hexagons in a plain in every direction translational simmetry is broken, so proably is rather difficult to find a good set of eigenvectors to do the corresponding fourier transform.

[@Orientaliszt]

@@yannickkamta2719 Graphene size domain is about 1 to 100 µm. For DFT calculations this is infinity!

[@Orientaliszt]

​@@SBLP24 Pentagons make positive curvatuve, but heptagons insure negative one, so globally the system is relaxed and polycristalline graphene remain more or less in the plane. If graphene grain size is sufficiently high, these curvature considerations remains negligible as compared to the small C60 molecule. Your objection on eigenvectors make sens.

[@billyheng4824]

besides metallic and semiconductor can it behave as non-metallic. Not include its broken to half.

[@palhardy4292]

Oh boy.....that intro and transition

[@baikeyuan]

牛逼的介绍