A New Twist Reveals Superconductivity’s SecretsThen in the past month, two papers published in the j
A New Twist Reveals Superconductivity’s SecretsThen in the past month, two papers published in the journals Nature and Science described a second related superconductor, a three-layer graphene sandwich with the “bread” sheets aligned and the filling sheet skewed by 1.56 degrees. The unmistakable electron-carrying prowess of twisted trilayer graphene confirms that the two-wafer system was not a fluke. “It was the first of a family of moiré superconductors,” said Jarillo-Herrero, a physicist at the Massachusetts Institute of Technology who also led one of the new experiments, “and this one is the second member of the family.” mportantly, this second sibling has helped to illuminate an underlying mechanism that could be what powers the superconductivity of these materials.In the months after the 2018 discovery, one group of theorists began to puzzle over the mechanism that made bilayer graphene superconduct. They suspected that one particular geometric trait might allow electrons to swirl into exotic maelstroms that behave in an entirely novel manner. This mechanism, which is unlike any of the (few) known schemes responsible for superconductivity, would explain the superconductive success of bilayer graphene, as well as the failure of other materials. It also predicted that graphene’s trilayer sibling would superconduct as well.But it remained just a theory — at least until labs had a chance to test it. “From what we know now, it seems like an exciting direction,” said Eslam Khalaf, a researcher at Harvard University who helped develop the model. “It’s not every day that we have a new way to get superconductivity.” -- source link
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