You may recognize graphite as the "lead" in a pencil, but besides helping you take notes or fill in countless bubbles on exam answer sheets, it is helping scientists grapple with the secrets of superconductivity.
Superconductivity happens when an electric current is transmitted through wires without the loss of any energy in the form of heat or resistance. Superconducting materials have the potential to revolutionize many aspects of our daily lives, from improving the electrical grid to making more powerful computers.
However, superconductivity generally requires very low temperatures, so low they may become impractical, and the exact mechanisms of superconductivity are not well understood for many superconducting materials.
In their recent publication in Nature , a collaboration of researchers, including UConn Department of Physics Professor Pavel Volkov, detail surprising findings about superconductivity in twisted trilayer graphene.
In 2018, attention focused on the rich physics of superconductivity in multilayer graphene, which is a single layer of carbon atoms. As a single layer, graphene is not superconducting; however, this changes when two layers are stacked and slightly twisted to form twisted bilayer graphene (TBG). Stacking three layers to make twisted trilayer graphene (TTG) together makes the system more stable and robust and was the subject for much of this study.
The twist leads to unique and unconventional superconducting properties in the twisted trilayer graphene. Volkov says that at a so-called "magic" twist angle, quantum interference effects lead to the motion of elections slowing down enormously as they move through the layers of graphene, allowing them to interact much more strongly with one another, which is likely the driving force of superconductivity.
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