Antiferromagnetic quantum criticality induced by onset of superconductivity around upper critical field:: non-Fermi liquid behavior of CeCoIn5 at H ≃ Hc2

It is argued that the non-Fermi liquid behavior observed in CeCoIn5 and its solid solution CeCo(In, Sn)(5) around the upper critical field H-c2 can be understood as the antiferromagnetic (AF) quantum criticality induced by the critical fluctuations associated with an onset of the d-wave superconductivity with B-1g(d(x2-y2)) or B-2g(d(xy)) symmetry. A basic idea is that the effect of SC fluctuations on the mode-coupling term of the AF susceptibility works to promote the AF-order while those effect on the RPA term works to suppress the AF tendency. On the basis of this idea, the pinning of AF-QC around H-c2 observed in CeCo(In, Sn)(5) can be qualitatively explained.