Magnetic Criticality and Unconventional Superconductivity in CeCoIn5: Study of 115In-Nuclear Quadrupole Resonance under Pressure
Magnetic Criticality and Unconventional Superconductivity in CeCoIn5: Study of 115In-Nuclear Quadrupole Resonance under Pressure
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DOI：
10.1143/jpsj.73.2073
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发表时间：
2004-08
影响因子：
1.7
通讯作者：
M. Yashima;S. Kawasaki;Y. Kawasaki;G. Zheng;Y. Kitaoka;H. Shishido;R. Settai;Y. Haga;Y. Ōnuki
中科院分区：
文献类型：
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作者：
M. Yashima;S. Kawasaki;Y. Kawasaki;G. Zheng;Y. Kitaoka;H. Shishido;R. Settai;Y. Haga;Y. Ōnuki
本文报道了用核四极共振（NQR）方法测量的重费米子（HF）超导体CeCoIn 5在压力（P）下超导特性的系统演化。P的应用显着抑制核自旋晶格弛豫速率1/T1，这是由反铁磁（AFM）自旋涨落（SF）特定的量子临界点（QCP）。它表明，AFM SF的显着抑制导致减少SC能隙或在耦合强度的库珀对。然而，由于HF带宽的增加，TC随着P的增加而增加。这有望使准粒子的寿命足够长。
We report the systematic evolution of the superconducting (SC) characteristics of the heavy-fermion (HF) superconductor CeCoIn 5 via nuclear-quadrupole-resonance (NQR) measurement under pressure ( P ). The application of P significantly suppresses the nuclear spin–lattice relaxation rate 1/ T 1 that is dominated by antiferromagnetic (AFM) spin fluctuations (SFs) specific to a quantum critical point (QCP). It is demonstrated that the marked suppression of AFM SFs leads to a reduction in the SC energy gap or in the coupling strength of the Cooper pair. T c , nevertheless, increases with increasing P due to the increase in HF bandwidth. This is expected to make the lifetime of quasi-particles sufficiently long.