We report on systematic evolutions of antiferromagnetic (AFM) spin fluctuations and unconventional superconductivity (SC) in heavy-fermion (HF) compounds CeRh1-xIrxIn5 via an In115 nuclear-quadrupole-resonance experiment. The nuclear spin-lattice relaxation rate 1/T1 has revealed the marked development of AFM spin fluctuations as approaching an AFM ordered state. Concomitantly, the superconducting transition temperature Tc and the energy gap Δ0 increase drastically from Tc=0.4K and 2Δ0/kBTc=5 in CeIrIn5 up to Tc=1.2K and 2Δ0/kBTc=8.3 in CeRh0.3Ir0.7In5, respectively. The present work suggests that the AFM spin fluctuations in close proximity to the AFM quantum critical point are indeed responsible for the strong-coupling unconventional SC in HF compounds.
ASJC Scopus subject areas
- Physics and Astronomy(all)