Researchers from Columbia University, Harvard University, Japan's National Institute for Materials Science and Austria's University of Innsbruck have studied the structural and electronic properties of twisted trilayer graphene using low-temperature scanning tunneling microscopy at twist angles for which superconductivity has been observed.
The discovery of superconductivity in two layers of graphene arranges in the "magic angle" of 1.1 degrees has become quite famous. With just two atom-thin sheets of carbon, researchers discovered a simple device to study the resistance-free flow of electricity, among other phenomena related to the movement of electrons through a material. Adding a third layer of graphene improves the odds of finding superconductivity, but the reason was unclear. Now, the researchers of the new study reveal new details about the physical structure of trilayer graphene that help explain why three layers are better than two for studying superconductivity.