One phenomenon in these materials is explained by a non-zero effective photon mass within them,and one type loses its properties at an upper critical field.
One phenomenon in these materials is explained by a non-zero effective photon mass within them,and one type loses its properties at an upper critical field. One model of them gives free energy interms of an order parameter. Another theory of them reproduces the isotope effect and gives therelationship between the energy gap and temperature. In that model, phonons mediate thecombination of electrons into (*) Cooper pairs. These materials expel magnetic fields in the Meissnereffect, and are divided into Type I and Type II varieties depending on the temperature of their phasetransition. Their uses include maglev trains and lossless power transmission. For 10 points, name thesematerials described by BCS theory, which have zero electrical resistance.
One phenomenon in these materials is explained by a non-zero effective photon mass within them,and one type loses its properties at an upper critical field.
superconductors [or word forms like superconductivity; accept Type I superconductivity, Type II superconductivity, or high-temperature superconductivity throughout]