Critical slowing-down and field-dependent paramagnetic fluctuations in the skyrmion host EuPtSi; SR and NMR studies

スキルミオンホスト物質EuPtSiにおける臨界減速と磁場依存した常磁性ゆらぎ; SRおよびNMRによる研究

比嘉 野乃花*; 伊藤 孝   ; 與儀 護*; 服部 泰佑; 酒井 宏典   ; 神戸 振作  ; Guguchia, Z.*; 髭本 亘  ; 中島 美帆*; 本間 佳哉*; 仲村 愛*; 本多 史憲*; 清水 悠晴*; 青木 大*; 垣花 将司*; 辺土 正人*; 仲間 隆男*; 大貫 惇睦*; 徳永 陽  

Higa, Nonoka*; Ito, Takashi; Yogi, Mamoru*; Hattori, Taisuke; Sakai, Hironori; Kambe, Shinsaku; Guguchia, Z.*; Higemoto, Wataru; Nakashima, Miho*; Homma, Yoshiya*; Nakamura, Ai*; Honda, Fuminori*; Shimizu, Yusei*; Aoki, Dai*; Kakihana, Masashi*; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika*; Tokunaga, Yo

We report the results of SR and Si NMR measurements carried out on the cubic chiral magnet EuPtSi. Our zero-field SR experiments revealed the development of critical slowing down of Eu spin fluctuations over a relatively wide critical region above . We also found from Si NMR that the spin fluctuations are strongly suppressed by magnetic field in the paramagnetic state above 20K. These characteristic spin dynamics observed over a wide region of temperature and magnetic field suggest the presence of magnetic frustration in the spin system. Such frustration would underlie the mechanism stabilizing the short-period skyrmion lattice observed in this compound.