We review the normal and superconducting properties in the noncentrosymmetric heavy-fermion CeRhSi 3. In the normal state, CeRhSi 3 exhibits the antiferromagnetic order at low temperatures (1.6K at ambient pressure) although its Kondo temperature is much higher than the ordering temperature T N. With applying pressure P, T N initially increases and subsequently decreases. The superconductivity arises at the pressures where the antiferromagnetic transition occurs. T N does not seem to fall to zero but becomes nearly constant with further application of pressure, and then T N vs P merges with the superconducting transition temperature T c vs P at 26 kbar where T c reaches the maximum. Nearly perfect magneticshielding associated with the superconductivity is observed below 26 kbar, suggesting that the bulk superconductivity is realized below T N. We observe an anomaly below T c in the resistivity as well as in the ac-susceptibility. The origin of the both anomalies seem to be the same but have not been clarified. The magnetic field-temperature (H-T) phase diagram of the superconducting state for fields along the tetragonal a-axis is unusual. It has a concave structure and the upper-critical-field H c2 at zero temperature exceeds the paramagnetic limiting field expected from the BCS model. The pressure dependence of H-T phase diagram implies that the paramagnetic effect exists and the effect is much reduced in CeRhSi 3. This result is consistent with the theoretical prediction for the noncentrosymmetric superconductor.
- Heavy fermion
- Noncentrosymmetric superconductor
ASJC Scopus subject areas
- Physics and Astronomy(all)