These materials are characterized by an equation that includes a hopping integral, the t-J model, itself derived from the Hubbard model. By comparing the coherence length to the London penetration depth, one can determine if these materials are Type 
These materials are characterized by an equation that includes a hopping integral, the t-J model, itself derived from the Hubbard model. By comparing the coherence length to the London penetration depth, one can determine if these materials are Type I or Type II. A critical temperature above the boiling point of nitrogen characterizes the high-temperature type of these materials, which include cuprate perovskites like YBCO. These materials expel interior magnetic fields through the Meissner Effect, a phenomenon explained by Cooper pairs in the BCS theory. For 10 points, name these materials which exhibit zero electrical resistance.
These materials are characterized by an equation that includes a hopping integral, the t-J model, itself derived from the Hubbard model.
{superconductor}s [or word forms]