Graphene
A single two-dimensional layer of carbon atoms bound in a hexagonal honeycomb crystal lattice.
Governing formula
E(k) = ± ℏ v_F |k| (Dirac Cone Dispersion)
SI unit
v_F ≈ 10⁶ m/s (Fermi Velocity)
In depth
Isolated by Andre Geim and Konstantin Novoselov in 2004. Electrons in graphene move as zero-effective-mass relativistic Dirac fermions at 1/300 the speed of light, yielding ultra-high carrier mobility (~200,000 cm²/V·s) and extreme tensile strength (~130 GPa).
Examples in the real world
Flexible transparent conductive electrodes, high-frequency transistors, and advanced carbon composite materials.