Superconductivity Is unpredictable at the edge

Topological materials are materials that have unusual properties that arise because their wavefunction—the physical law guiding the electrons—is knotted or twisted. Where the topological material meets the surrounding space, the wavefunction must unwind. To accommodate this abrupt change, the electrons at the edge of the material must behave differently than they do in the main bulk of the material. This results in what scientists call edge states. If the topological material is also a superconductor, the bulk and the edge are both superconducting but they behave differently.