The noncentrosymmetric heavy fermion superconductor CeRhSi3 exhibits an extremely large superconducting upper critical field Bc2 for the magnetic field along the c axis. This remarkable feature is ascribed to the noncentrosymmetric (Rashba-type) crystal structure which can avoid the paramagnetic pair-breaking effect. The pressure dependence of the B c2(T) curve, however, is very complicated and remains as an unresolved issue. Recently, we found a bend in the Bc2(T) curve which emerges at a pressure where the antiferromagnetic order disappears. Furthermore, an anomaly in the electrical resistivity in the normal state emerges above the magnetic field of the bend point. The obtained magnetic and superconducting phase diagram thus appears to have complicated structure especially in the vicinity of the pressure where the antiferromagnetic order vanishes.
- Heavy fermion superconductivity
- Upper critical field