Graphene is a semi-metal or zero band gap semiconductor. Understand electronics
The structure of graphene is the starting point for finding its energy band structure.
Graphite. As early as 1947, Wallace recognized E-K.
For the low energy near six corners of two-dimensional plane, the relationship is linear.
Hexagonal Brillouin zone leads to zero effective mass of electrons.
Cave. Due to this linear (or "conical") dispersion relation at low energy,
The behavior of electrons and holes (two of which are not equivalent) near these six points.
Relativistic particles described by Dirac equation with spin 1/2.
Particles. Therefore, electrons and holes are called Dirac fermion.
The corner of Brillouin zone is called Dirac point.