There are two forms of solids: "crystals" in which atoms are arranged periodically and regularly, and "amorphous" in which atoms are arranged in a disorderly manner.However, in 2, a form called "quasicrystal" was discovered, which is neither of them.Quasicrystals do not have the periodicity of crystals, but unlike amorphous ones, they have a certain degree of regularity.

　The quasicrystals known so far have been complex alloys, but the only quasicrystal material realized in this study is carbon.Graphene, a two-dimensional substance of carbon (thin film with a thickness of one atom), is a crystal in which carbon atoms are lined up in a honeycomb lattice.A quasicrystal with 2-fold symmetry was realized by creating a system in which two graphenes overlap each other at 1 degrees by a special synthesis method. 2-fold symmetry is a structure in which the same picture appears 30 times while rotated 12 degrees.Graphene's electrons behave as special massless particles called relativistic Dirac particles.In this research, we realized a new physical system called quasicrystal by Dirac particles.

　Due to its unique geometric structure, quasicrystals are attracting attention for their physical properties such as electrical and thermal properties.Studies to date have shown that quasicrystals have unusually high electrical resistance and low friction compared to crystals with the same elemental composition, but there are still many unclear points regarding their physical properties.With this discovery, the range of quasicrystals will be greatly expanded, and it is expected that new properties not found in ordinary substances will be discovered.

Paper information:[Science] Dirac electrons in a dodecagonal graphene quasicrystal