Magnetic-field enhanced aniferromagnetism in non-centrosymmetric heavy-fermion superconductor CePt$_3$Si

TL;DR

This study investigates how magnetic fields influence antiferromagnetic correlations in the non-centrosymmetric heavy-fermion superconductor CePt$_3$Si, revealing a strong directional dependence and a significant enhancement of antiferromagnetic order.

Contribution

It provides the first detailed neutron scattering analysis of magnetic field effects on static and dynamic spin correlations in CePt$_3$Si, highlighting the anisotropic enhancement of antiferromagnetism.

Findings

Magnetic field increases AFM peak intensity, especially for B//[0 0 1].

AFM moment more than doubles at 6.6 T for B//[0 0 1].

Inelastic response shows no significant field variation up to 3.8 T.

Abstract

The effect of magnetic field on the static and dynamic spin correlations in the non-centrosymmetric heavy-fermion superconductor CePt$_3$Si was investigated by neutron scattering. The application of a magnetic field B increases the antiferromagnetic (AFM) peak intensity. This increase depends strongly on the field direction: for B${\parallel}$[0 0 1] the intensity increases by a factor of 4.6 at a field of 6.6 T, which corresponds to more than a doubling of the AFM moment, while the moment increases by only 10 % for B${\parallel}$[1 0 0] at 5 T. This is in strong contrast to the inelastic response near the antiferromagnetic ordering vector, where no marked field variations are observed for B${\parallel}$[0 0 1] up to 3.8 T. The results reveal that the AFM state in CePt$_3$Si, which coexists with superconductivity, is distinctly different from other unconventional superconductors.