Superconducting Graphene

Synopsis

Despite years of considerable investigation, unconventional superconductivity remains a controversial phenomenon. A recent study demonstrated that twisting and aligning two sheets of graphene at a small angle forms a two-dimensional crystal structure for which the electron-phonon interactions, fundamental to the conventional theory, cannot account for the observed intrinsic superconductivity. This twisted bilayer graphene exhibits flat energy bands close to Fermi energy when twisted at a special angle, referred to as the magic angle. A variable zero-resistance state with a critical temperature of up to 1.7 K was observed, like the cuprates family of superconductors, by modifying the doping of the material. In this talk, I will discuss the crystal structure and electrodynamics of twisted bilayer graphene. This fully tunable 2D carbon-based material offers a remarkable opportunity to investigate strongly correlated materials and may provide new insights into the physics of high-critical-temperature superconductivity.