Tagged Questions
4
votes
2answers
138 views
Graphene +1 extra carbon bond
I'm not a physicist just a curious mind, so please go easy!
I was just watching a BBC Horizon Documentary that featured a piece on the recently discovered material Graphene. One of the facts ...
0
votes
0answers
96 views
Wave function ansatz for disclinated graphene with spin
I am currently investigating spin dynamics in disclinated graphene. More information about my approach can be found in my other post. I would like to know if my approach is somewhat correct to find ...
3
votes
1answer
108 views
Graphene with a disclination and the spin-orbit coupling
I am trying to follow the methods used in this paper (http://arxiv.org/pdf/1208.3023.pdf) to construct the Hamiltonian of a graphene cone, but taking into account the spin-orbit coupling.
The paper ...
1
vote
1answer
477 views
Effective Mass and Fermi Velocity of Electrons in Graphene:
In graphene, we have (in the low energy limit) the linear energy-momentum dispersion relation: $E=\hbar v_{\rm{F}}|k|$. This expression arises from a tight-binding model, in fact $E =\frac{3\hbar ...
1
vote
2answers
183 views
Thomas-Fermi approximation and the dielectric function (+ small bit on graphene)
1) With the dielectric function, which is a function of wavenumber and frequency,how is it possible to take the limit of either to zero without changing the other one? I thought that frequency and ...
1
vote
1answer
1k views
What is the approximate electrical conductivity $\sigma$ of graphene in S/m or S/cm?
I am trying to find an approximate value of the electrical conductivity $\sigma$ of graphene in units of S/m or S/cm. This table on Wikipedia gives $\sigma$ values for a variety of materials ...
4
votes
1answer
508 views
Tight Binding Model in Graphene
I'm following a calculation done by a guy who's done it a bit different than what I've done before (used nearest neighbour vectors and a DFT instead of what I will show below), I'm not quite sure how ...
3
votes
2answers
791 views
Why electrons are relativistic in Graphene and non relativistic in vacuum?
If a free region in space has a potential difference of one volt, an electron in this region will acquire kinetic energy of 1 eV. Its speed will be much smaller than the speed of light hence it will ...
3
votes
1answer
279 views
What is the boundary condition of graphene flake with zigzag edges?
It is a question about free carrier behavior in graphene flakes. (or may be called charge confinement)
Say if we have a perfect hexagonal free standing graphene flake terminated with zigzag edges. ...
11
votes
1answer
879 views
Graphene and Klein bottle?
I am trying to understand graphene as a topological insulator.
The spin orbital interaction in graphene is very small (~10mK?). But if we consider that, then graphene should be a topological ...
