Superconductivity and normal state properties of non-centrosymmetric CePt3Si: a status report

Ternary CePt3Si crystallizes in the tetragonal P4mm structure which lacks a center of inversion. Antiferromagnetic order sets in at TN approx 22 K followed by superconductivity (SC) below Tc approx 0.75 K. Large values of H'c2 approx -8.5 T/K and Hc2(0) approx 5T were derived, referring to Cooper pairs formed out of heavy quasiparticles. The mass enhancement originates from Kondo interactions with a characteristic temperature TK approx 8 K. CePt3Si follows the general features of correlated electron systems and can be arranged within the Kadowaki-Woods plot next to the unconventional SC UPt3. NMR and mSR results show that both magnetic order and SC coexist on a microscopic scale without having spatial segregation of both phenomena. The absence of an inversion symmetry gives rise to a lifting of the degeneracy of electronic bands by spin-orbit coupling. As a consequence, the SC order parameter may have uncommon features as indicated from a very unique NMR relaxation rate 1/T1 and a linear temperature dependence of the penetration depth λ