CuMoOの中性子非弾性散乱

Inelastic neutron scattering study on CuMoO

黒江 晴彦*; 浜崎 智幸*; 長谷 正司*; 金子 耕士   ; 目時 直人   ; 松田 雅昌; 加倉井 和久; 岡 邦彦*; 伊藤 利充*; 永崎 洋*

Kuroe, Haruhiko*; Hamasaki, Tomoyuki*; Hase, Masashi*; Kaneko, Koji; Metoki, Naoto; Matsuda, Masaaki; Kakurai, Kazuhisa; Oka, Kunihiko*; Ito, Toshimitsu*; Eisaki, Hiroshi*

低次元反強磁性体物質CuMoOの中性子非弾性散乱の結果を報告する。この系の磁気励起分散関係は、交換相互作用J3による孤立ダイマーによるフラットな分散関係(Et=J3=5.8meV,図中の点線)と、鎖間相互作用を考慮した擬一次元磁性鎖の分散関係との間に、波数に依存した相互作用を働かせることで再現できる。当日は、磁気励起の分散関係のほかに、低エネルギー励起の詳細を紹介する。

We have measured inelastic neutron scattering in CuMoO to study its magnetic-excitation dispersion curves. This material can be treated as a complex of the following two spin subsystems. (1) Quasi-one-dimensional antiferromagnetic (AF) spin chain with the intrachain interaction pJ4 = 6.3 meV, where p is the renormalization factor depending on the system dimension, together with the ferromagnetic and AF interchain interactions -Ja = J 0.01pJ4. (2) AF spin dimers with the interaction J3 = 5.8 meV. The hybridization parameter, representing the intersubsystem interaction between these subsystems, is estimated as Eint sin (k), where Eint = 1.6 meV. The modulation of the molecular field generated by the spin precession in the excited state of the quasi-one-dimensional spin chain plays an important role in this hybridization.