Superconductivity

P.C. Hammel, M. Takigawa, R.H. Heffner, Z. Fisk, K.C. Ott, "Spin dynamics at oxygen sites in YBa2Cu3O7," Physical Review Letters, 63, 1992-5, 30 October 1989.

P. Chris Hammel (Los Alamos National Laboratory, N.Mex.): "This letter describes the results of nuclear magnetic resonance (NMR) experiments in the high-temperature superconductor YBa2Cu3O7. Magnetic resonance is unique in its ability to microscopically probe magnetic behavior at different crystallographic sites in this complex crystal. The results are important because they provide very specific information about the nature of magnetic interactions in these materials. "The high-temperature superconductors (such as YBa2Cu3O7) result from antiferromagnetic, insulating `parent' compounds (such as YBa2Cu3O6) into which carriers (either holes or electrons) are doped. The close relationship between the superconducting compound and the antiferromagnet suggests that magnetic mechanisms may play a role in the superconductive pairing. Our experiments provided detailed information about the antiferromagnetic interactions in the normal state of YBa2Cu3O7. We...