We report Cu nuclear-quadrupole-resonance results under pressure (P) on a homogeneous CeCu2Si2 (Tc=0.65 K) that revealed critical magnetic fluctuations at the border to an antiferromagnetic (AF) phase. This exotic superconducting (SC) phase evolves into the typical heavy-fermion SC phase at minute pressures exceeding Pc∼0.2 GPa. The nuclear spin-lattice relaxation data in a P range 0.85 - 2.58 GPa are shown to be accountable by the spin-fluctuation theory based on the nearly AF Fermi-liquid model. In 0≤P< Pc∼0.2 GPa, by contrast, we conclude that the exotic SC phase manifests itself under the unconventional normal state where AF waves propagate over a long range without any trace of AF order and thereby the heavy-fermion state breaks up.
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2001|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics