Call graphene the “miracle material” for a reason – he is ultra-thin, ultra-strong and has a very unusual electrical properties. Researchers from MIT before been found particularly strange pattern that occurs in twisted graphene but is now significantly deepened in his study.
Graphene consists of layers of carbon with a thickness of only one atom. This makes it actually two-dimensional, and the current in it, electrons can only move back and forth and from side to side, but cannot move up or down. This makes graphene extremely high conductivity.
However, if you put a few layers of graphene and its electrical properties will change. If you move the top layer relative to the bottom at the “magic angle” 1.1 degrees – material gets a new amazing quality. This bilayer structure will suddenly gain the ability to move out of state an electrical insulator in a condition of the superconductor. This property of graphene was discovered in 2018.
Recent study found an even more interesting fact. If you put four of the graphene sheet and bend them at the “magic angle”, the whole structure becomes an insulator, as in the case of two layers. But now the degree of electrical isolation can be finely configured using the electromagnetic field, which can be done with a two-layer stack.
The study of the new pattern is still in a very early stage. However, scientists claim that once such twisted graphene systems will allow you to create a very unusual electronic devices. Work on this subject was published in the journal Nature.
Source — MIT