受挫的 Kagomé 晶格反铁磁体 KFe3(OH)6(SO4)2 中的自旋波

Spin waves in the frustrated kagomé lattice antiferromagnet KFe3(OH)6(SO4)2.

作者信息

Matan K, Grohol D, Nocera D G, Yildirim T, Harris A B, Lee S H, Nagler S E, Lee Y S

机构信息

Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

出版信息

Phys Rev Lett. 2006 Jun 23;96(24):247201. doi: 10.1103/PhysRevLett.96.247201. Epub 2006 Jun 19.

DOI:10.1103/PhysRevLett.96.247201

PMID:16907274

Abstract

The spin wave excitations of the S=5/2 kagomé lattice antiferromagnet KFe3(OH)6(SO4)2 have been measured using high-resolution inelastic neutron scattering. We directly observe a flat mode which corresponds to a lifted "zero energy mode," verifying a fundamental prediction for the kagomé lattice. A simple Heisenberg spin Hamiltonian provides an excellent fit to our spin wave data. The antisymmetric Dzyaloshinskii-Moriya interaction is the primary source of anisotropy and explains the low-temperature magnetization and spin structure.

摘要

利用高分辨率非弹性中子散射测量了S = 5/2的 kagomé晶格反铁磁体KFe3(OH)6(SO4)2的自旋波激发。我们直接观测到一个对应于提升的“零能量模式”的平坦模式，证实了对kagomé晶格的一个基本预测。一个简单的海森堡自旋哈密顿量能很好地拟合我们的自旋波数据。反对称的Dzyaloshinskii-Moriya相互作用是各向异性的主要来源，并解释了低温磁化和自旋结构。