Band Structure of Graphene
Band Structure of Graphene
Graphene consists of a single layer of carbon atoms arranged in a honeycomb lattice, with lattice constant . This type of lattice structure has two atoms as the bases ( and , say). In this Demonstration, the band structure of graphene is shown, within the tight-binding model. The conduction and the valence bands touch each other at six points (arranged in a hexagonal pattern) in momentum space, known as Dirac points. Three out of these six points are called points and the other three are called points. In each set, the points are one reciprocal lattice vector apart. The band touching at the Dirac points gives rise to energy degeneracy at these points. The dispersion around them is found to be linear.
a=1.42Å
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B
K
K'
This Demonstration shows how the band structure changes near the Dirac points with changes in certain hopping parameters:
t
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B
f
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A
A
f
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B
B
In the result, corresponds to the conduction band (in orange) and corresponds to the valence band (in blue).
E
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E
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