115In NQR studies of CeRhIn5 and CeCoIn5 under high pressure

We have carried out In-115 nuclear quadrupole resonance (NQR) measurements in CeRhIn5 and CeCoIn5 under presure P. The nuclear spinlattice relaxation rates, 1/T-1, of In-115 indicated that the anisotropic superconductivity with line nodes occurred near an antiferromagnetic state. The application of P suppressed the antiferromagnetic, AF, spin fluctuations and moves the system away from the AF state to the non-magnetic Fermi liquid state. The P dependence of 1/T-1 in the superconducting state of CeCoIn5 shows that the magnitude of the superconducting energy gap scales with its T-C up to 3.0 GPa. (c) 2005 Elsevier B.V. All rights reserved.