Local antiferromagnetism in high-Tc cuprate superconductors and the magnetic phases of U-based heavy-fermion compounds

We investigate the possibility of the local induction of the antiferromagnetism (AF) in high-T-c superconductors and U-based heavy fermion compounds. In the former case, assuming the d-wave superconductivity in the bulk system, we find that AF can locally appear around surfaces and impurities and can coexist with the d-wave superconductivity. The induced AF is enhanced near the surface by the presence of superconductivity. Furthermore, the zero-energy bound state near the (110) surface of d(x2-y2)-wave superconductors is split by the local AF, as was observed in YBa2Cu3O7. We also show in a model that this phenomenon is mathematically equivalent to (1) the surface s+id-wave superconductivity, which has been also proposed in the high-T-c cuprates, and (2) the local AF in the unconventional spin-density wave, which has been proposed as a candidate for the magnetism in URu2Si2. In particular, the case (2) can explain the recent experiment for URu2Si2, which observes that the temperature at which the antiferromagnetic moment appears is lower than the phase-transition temperature. [S0163-1829(99)01846-9].