Direct observation of a superconducting gap in weakly doped YBa2Cu3Oy by using infrared spectroscopy

초록

We report on an infrared study of a superconducting gap state for YBa2Cu3Oy as a function of doping. In the weakly doped region a superconducting gap is identified directly in the optical conductivity and its value increases with the doping. Superconducting condensation is associated with coherent electronic excitation in the nodal region, exclusive of the antinodal region where the pseudogap is open.

키워드