Low Temperature Susceptibility of the Noncentrosymmetric Superconductor CePt_3Si

TL;DR

This study investigates the low-temperature magnetic susceptibility of CePt_3Si, revealing a fragile Meissner state at very low temperatures and a field-dependent susceptibility described by a specific power law.

Contribution

First detailed ac susceptibility measurements of CePt_3Si at millikelvin temperatures, highlighting its fragile superconducting state and field dependence.

Findings

Full Meissner state below 0.3 T_c

Susceptibility diminishes rapidly with applied field

Power law describes field dependence of susceptibility

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, \chi', is quite fragile to applied field, with \chi' diminishing rapidly in fields of a few kG. Interestingly, the field dependence of \chi' is well described by the power law, 4\pi\chi'=(B/B_c)^{1/2}, where Bc is the field at which the onset of resistance is observed in transport measurements.