Universal scaling behavior under pressure in the heavy-fermion antiferromagnet CeRhSi; Si NMR study

重い電子系反強磁性体における圧力下の普遍的スケーリング的振る舞いについて; Si核核磁気共鳴研究

酒井 宏典   ; 松本 裕司*; 芳賀 芳範   ; 徳永 陽  ; 神戸 振作  

Sakai, Hironori; Matsumoto, Yuji*; Haga, Yoshinori; Tokunaga, Yo; Kambe, Shinsaku

重い電子系反強磁性体CeRhSiにおいて、Si核核磁気共鳴(NMR)を用いて、圧力下相図について微視的に調べた。NMRデータから、反強磁性伝搬ベクトルに依らない単一サイト近藤効果の特徴的温度スケールを導出した。圧力下の反強磁性臨界点においての発散的異常は見られず、重い電子系の典型的なDoniach描像と矛盾しない結果が得られた。

The microscopic origin of a magnetic phase diagram under pressure in a heavy fermion antiferromagnet CeRhSi was investigated using the Si nuclear magnetic resonance (NMR) technique. We investigated the temperature and pressure dependencies of -independent local fluctuations caused by the single-site Kondo effect. A universal scaling behavior observed on the energy scale of the local fluctuations in an entire pressure region demonstrates that a characteristic energy scale of Kondo interactions monotonically increases by applying pressure without a critical anomaly around the quantum critical pressure of antiferromagnetism. Our NMR result agrees with the Doniach picture of the heavy-fermion phase diagram, where the progressive delocalization of the -electrons occurs across , accompanied by the development of antiferromagnetic correlations among the -electrons.