Novel Pressure Phase Diagram of Heavy Fermion Superconductor CePt${}_3$Si Investigated by ac Calorimetry

Abstract

The pressure dependences of the antiferromagnetic and superconducting transition temperatures have been investigated by ac heat capacity measurement under high pressures for the heavy-fermion superconductor CePt${}_3$Si without inversion symmetry in the tetragonal structure. The Néel temperature $T_{\mathrm{N}}$ = 2.2 K decreases with increasing pressure and becomes zero at the critical pressure $P_{\mathrm{AF}}$ $\simeq$ 0.6 GPa. On the other hand, the superconducting phase exists in a wider pressure region from ambient pressure to about 1.5 GPa. The pressure phase diagram of CePt${}_3$Si is thus very unique and has never been reported before for other heavy fermion superconductors.

4 pages and 3 figures. This paper will be published in the July issue of J. Phys. Soc. Jpn