Magnetic excitations in the noncentrosymmetric magnet SrMnSiO

川又 雅広*; Pang, X.*; 村川 寛*; 河村 聖子   ; 中島 健次   ; 増田 英敏*; 藤田 全基*; 花咲 徳亮*; 小野瀬 佳文*; 南部 雄亮*

Kawamata, Masahiro*; Pang, X.*; Murakawa, Hiroshi*; Kawamura, Seiko; Nakajima, Kenji; Masuda, Hidetoshi*; Fujita, Masaki*; Hanasaki, Noriaki*; Onose, Yoshinori*; Nambu, Yusuke*

Magnetic excitations in the noncentrosymmetric magnet SrMnSiO were investigated through inelastic neutron scattering measurements. Major magnetic excitations are limited up to the energy transfer of 0.5 meV, and two magnon branches under zero magnetic field were well explained in the framework of linear spinwave theory. The magnitudes of the square-lattice in-plane and interplane nearest-neighbor interactions, spin anisotropy term, and the Dzyaloshinskii-Moriya interaction are, respectively, estimated to be J = 45.54(5) eV, J = 0.52(1) eV, = 4.98(11) eV, D = 0.02(9) eV, and D = 4.10(1) eV, and calculations using these parameters reproduce experimental data quite well. SrMnSiO appears to have the smallest energy scale among the melilite-type compounds, and the small J/J = 0.0114(2) indicates the strong two dimensionality.