For ten points, name these materials which, when cooled below the critical temperature, have no resistance to current.
Muon spin spectroscopy can be used to measure the London penetration depth of these materials, and a current flowing through two of them forms a Josephson junction. The type-I form of these materials can reach an intermediate state described by Landau, while flux pinning requires the type-II form of them. The BCS theory posits that they are formed by the condensation of (*) Cooper pairs, and one of these objects can be levitated over a magnet after expulsion of their magnetic fields in the Meissner Effect. For ten points, name these materials which, when cooled below the critical temperature, have no resistance to current.
Muon spin spectroscopy can be used to measure the London penetration depth of these materials, and a current flowing through two of them forms a Josephson junction.
superconductors (accept word forms) &lt;HX&gt;