论文标题
Ca-kapellasite中单手抗磁性状态的各向异性磁激发
Anisotropic magnetic excitations from single-chirality antiferromagnetic state in Ca-kapellasite
论文作者
论文摘要
我们提出了$^{35} $ cl nmr研究，用于旋转$ s = 1/2 $ perfect kagome抗fiferromagnet ca-kapellasite（cacu $ _ {3} $（oh）$ _ {6} $ _ {6} $ cl $ cl $ _ {2}} K.基态的静态磁结构已被确定为手性订购的$ q = 0 $状态，该状态是由有限的dzyaloshinskii-moriya相互作用选择的。通过核自旋晶格松弛速率测量研究了有序状态下的低能磁激发。除了在Kagome平面中的分散性自旋波贡献外，我们还检测到垂直于Kagome平面的磁波动中的温度依赖性较弱的贡献。来自共面旋转结构的低能磁激发归因于零模式，该模式来自该kagome抗fiferromagnet中的平坦带。
We present a $^{35}$Cl NMR study for spin $S=1/2$ perfect kagome antiferromagnet Ca-kapellasite (CaCu$_{3}$(OH)$_{6}$Cl$_{2}\cdot$0.6H$_{2}$O) with a magnetic transition at $T^{\ast}=7.2$ K. The static magnetic structure in the ground state has been determined to be a chirality-ordered $Q=0$ state, which is selected by a finite Dzyaloshinskii-Moriya interaction. The low-energy magnetic excitations in the ordered state are investigated by the nuclear spin-lattice relaxation rate measurement. We detect a weakly temperature dependent contribution in the magnetic fluctuations perpendicular to the kagome plane in addition to the dispersive spin-wave contribution in the kagome plane. The low-energy magnetic excitations from the coplanar spin structure are attributed to the zero mode originating from the flat band in this kagome antiferromagnet.
