The ĉ-axis penetration depth as a function of temperature and doping was investigated. It was found that the in the cuprate superconductor YBa 2Cu3O6+x the hole doping in the CuO2 layers was controlled by both oxygen content and the degree of oxygen ordering. The ordering occur at room temperature to tune the hole doping so that the superconducting critical temperature rises from 0 to 20 k. It was also found that the d-wave superconductor survives to very low doping, with no sign of another ordered phase interfering with the nodal quasiparticles.
Publication Source (Journal or Book title)
Physical Review Letters
Hosseini, A., Broun, D., Sheehy, D., Davis, T., Franz, M., Hardy, W., Liang, R., & Bonn, D. (2004). Survival of the d-wave superconducting state near the edge of antiferromagnetism in the cuprate phase diagram. Physical Review Letters, 93 (10) https://doi.org/10.1103/PhysRevLett.93.107003