Dirac materials are a class of solids in which the electrons behave as if they are relativistic, massless particles described by the Dirac equation. In these materials, the energy of electrons depends linearly on their momentum near specific points in the electronic band structure called Dirac points.
At these points, the conduction and valence bands touch in a cone-like shape, forming what’s known as a Dirac cone. This leads to unique and highly tunable electrical properties, such as high carrier mobility and conductivity.
Graphene is a prime example of a Dirac material, where electrons move at an effective “light speed” within the lattice. Other examples include topological insulators under certain conditions and some three-dimensional Dirac semimetals.
Because the electrons in Dirac materials do not behave like conventional particles with mass, they exhibit quantum effects usually reserved for high-energy physics, but at accessible laboratory scales. This makes Dirac materials important both for fundamental research and for potential applications in electronics and quantum technologies.