Effect of magnetic field on antiferromagnetism in non-centrosymmetric heavy-fermion superconductor CePtSi

反転対称性を持たない重い電子系超伝導体CePtSiの反強磁性状態における磁場効果

金子 耕士   ; Stockert, O.*; Arndt, J.*; Borth, R.*; Skoulatos, M.*; Habicht, K.*; Kiefer, K.*; Schneidewind, A.*; Etzdorf, D.*; 竹内 徹也*; 松田 達磨; 芳賀 芳範   ; 摂待 力生*; 大貫 惇睦*; 目時 直人   

Kaneko, Koji; Stockert, O.*; Arndt, J.*; Borth, R.*; Skoulatos, M.*; Habicht, K.*; Kiefer, K.*; Schneidewind, A.*; Etzdorf, D.*; Takeuchi, Tetsuya*; Matsuda, Tatsuma; Haga, Yoshinori; Settai, Rikio*; Onuki, Yoshichika*; Metoki, Naoto

The heavy-fermion superconductivity in CePtSi with a non-centrosymmetric structure attracts a lot of attention since novel superconducting properties are expected under this symmetry. Another characteristics of the superconductivity in CePtSi is its coexistence with long-range antiferromagnetic order. Therefore detailed antiferromagnetic properties and its interplay with superconductivity are of strong interest to investigate. The magnetic structure of CePtSi is represented by =(0,0,1/2). We have observed that the 0 0 1/2 antiferromagnetic reflection exhibits a peculiar response to an external magnetic field; its intensity increases with magnetic fields. These results imply unusual antiferromagnetism in CePtSi.