Low Temperature Susceptibility of the Noncentrosymmetric Superconductor CePt_3Si

Abstract

We report ac susceptibility measurements of polycrystalline CePt_3Si down to 60 mK and in applied fields up to 9 T. In zero field, a full Meissner state emerges at temperatures T/Tc < 0.3, where Tc=0.65 K is the onset transition temperature. Though transport measurements show a relatively high upper critical field Bc2 ~ 4-5 T, the low temperature susceptibility, χ&#39;, is quite fragile to applied field, with χ&#39; diminishing rapidly in fields of a few kG. Interestingly, the field dependence of χ&#39; is well described by the power law, 4πχ&#39;=(B/B_c)^{1/2}, where Bc is the field at which the onset of resistance is observed in transport measurements.