NMR study of antiferromagnetic superconductor under high pressure and at Low temperatures

在重费米子超导体中，超导性与磁性的相互作用是一个令人着迷的课题。特别是，铁磁或反铁磁自旋涨落的存在下，导致的预测，一个非传统的库珀对状态与非s波对称性实现的系统。我们研究了T=Co，Rh和Ir的CeTIn_5体系中的这些现象，从NMR和NQR测量中得到了该体系中实现了d波超导电性。对CeCoIn_5中~（13）In的自旋-晶格弛豫速率的压力依赖性<115>的研究表明，该体系在常压下处于量子临界点，随着压力的增加而变为非磁性.<29>对URu_2Si_2高压下的~ 13 Si NMR研究表明，在低温下实现了非磁性态和反铁磁态的共存.反铁磁相的体积分数随着压力的增加而迅速增加。

The interplay between the superconductivity and the magnetism in the heavy fermion superconductors is a fascinating subject. In particular, the presence of ferromagnetic or antiferromagnetic spin fluctuations has led to the prediction that an unconventional Cooper pair state with non s-wave symmetry is realized in the system. We have study these phenomena in CeTIn_5 system with T=Co, Rh and Ir. We obtained the d-wave superconductivity is realized in the system from NMR and NQR measurements. The pressure dependence of the nuclear spin-lattice relaxation rate of ^<115>In in CeCoIn_5 has shown that the system locates just the Quantum critical point at ambient pressure and becomes non-magnetic with increasing pressure.The ^<29>Si NMR study of URu_2Si_2 under high pressure has shown that co-existence of the non-magnetic and the antiferromagnetic states is realized at low temperature. The volume fraction of antiferromagnetic phase increases rapidly with increasing pressure.