Antiferromagnetic quantum criticality induced by onset of superconductivity around upper critical field: non-Fermi liquid behavior of CeCoIn5 at H approx. = 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 Hc2 can be understood as the antiferromagnetic (AF) quantum criticality induced by the critical fluctuations associated with an onset of the d-wave superconductivity with B1g(dx2-y2) or B2g(dxy) 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 Hc2 observed in CeCo(In,Sn)5 can be qualitatively explained