title: Enhancing the superconducting transition temperature of CeRh 1-x IrxIn5 due to the strong-coupling effects of antiferromagnetic spin fluctuations: an 115In nuclear quadrupole resonance study.
abstract: We report on systematic evolutions of antiferromagnetic (AFM) spin fluctuations and unconventional superconductivity (SC) in heavy-fermion (HF) compounds CeRh(1-x)Ir(x)In(5) via an (115)In nuclear-quadrupole-resonance experiment. The nuclear spin-lattice relaxation rate 1/T(1) has revealed the marked development of AFM spin fluctuations as approaching an AFM ordered state. Concomitantly, the superconducting transition temperature T(c) and the energy gap Delta0 increase drastically from T(c)= 0.4K and 2Delta0/k(B)T(c)=5 in CeIrIn(5) up to T(c) =1.2K and 2Delta0/k(B)T(c) =8.3 in CeRh(0.3)Ir(0.7)In5 , 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.
authors.affiliation: Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Kawasaki
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Yashima
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Mugino
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Mukuda
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kitaoka
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shishido
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Onuki