Nature's definitive proof: experiments reveal the secrets of graphene's "magic corner" superconductor!

Now, a new experiment at Princeton university has revealed how this so-called "magic horn" of twisted bilevel graphene can produce superconductivity, and Princeton scientists have provided solid evidence for this. Their study was published in the journal nature on July 31, 2019.

There's even a name for this field, "twistronics."Part of the excitement is that the material is easier to study than existing superconductors because it has only two layers and only one atom, carbon.B. Andrei Bernevig, a professor of physics who specializes in explaining the theory of complex materials, said the main feature of the new material is that it is the playground where people have been thinking about physics for the past 40 years.

The superconductivity of the new material appears to operate through a mechanism very different from that of traditional superconductors.Traditional superconductors are currently used in powerful magnets and other limited applications.The new material is similar to copperate, a copper-based high-temperature superconductor discovered in the 1980s.
The discovery of copperates led to the 1987 Nobel Prize in physics.The new material consists of two atom-thick pieces of carbon, known as graphene.Graphene was also the reason for the 2010 Nobel Prize in physics.Graphene has a flat cellular structure, like a wire fence.
Many simple metals are also superconducting, but all high-temperature superconductors discovered so far, including copper, have shown highly entangled states caused by electrons repelling each other.
Strong interaction between electrons seems to be the key to achieving higher temperature superconductivity.
To solve this problem, the Princeton researchers used a scanning tunneling microscope.
The microscope is so sensitive that it can image individual atoms on the surface.
The team scanned samples of the "magic horn" of twisted graphene and controlled the number of electrons by applying a voltage to nearby electrodes.
This study provides microscopic information that distorts the electronic behavior of bilayer graphene, whereas most other studies so far have only monitored macroscopic conductivity.
By adjusting the number of electrons to very low or very high concentrations, the electrons are observed to behave almost independently, as they do in simple metals.
However, when the critical concentration of superconducting electrons is found in the system, the electrons suddenly show signs of strong interaction and entanglement.
At concentrations where superconductivity occurs, the electron energy levels are found to become surprisingly widespread, and these signals confirm strong interactions and entanglement.
Still, while these experiments open the door to further research, more research is needed to understand in detail the types of entanglement that are taking place.
There is much that is not known about these systems, and it is far from scratching the surface of what can be learned through experimental and theoretical modeling.