Scheie Allen, Ziebel Michael, Chica Daniel G, Bae Youn June, Wang Xiaoping, Kolesnikov Alexander I, Zhu Xiaoyang, Roy Xavier
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Department of Chemistry, Columbia University, New York, NY, 10027, USA.
Adv Sci (Weinh). 2022 Sep;9(25):e2202467. doi: 10.1002/advs.202202467. Epub 2022 Jul 7.
CrSBr is an air-stable two-dimensional (2D) van der Waals semiconducting magnet with great technological promise, but its atomic-scale magnetic interactions-crucial information for high-frequency switching-are poorly understood. An experimental study is presented to determine the CrSBr magnetic exchange Hamiltonian and bulk magnon spectrum. The A-type antiferromagnetic order using single crystal neutron diffraction is confirmed here. The magnon dispersions are also measured using inelastic neutron scattering and rigorously fit the excitation modes to a spin wave model. The magnon spectrum is well described by an intra-plane ferromagnetic Heisenberg exchange model with seven nearest in-plane exchanges. This fitted exchange Hamiltonian enables theoretical predictions of CrSBr behavior: as one example, the fitted Hamiltonian is used to predict the presence of chiral magnon edge modes with a spin-orbit enhanced CrSBr heterostructure.
CrSBr是一种在空气中稳定的二维范德华半导体磁体，具有巨大的技术潜力，但其原子尺度的磁相互作用（这是高频开关的关键信息）却鲜为人知。本文提出了一项实验研究，以确定CrSBr的磁交换哈密顿量和体磁振子谱。在此，利用单晶中子衍射证实了A 型反铁磁序。还使用非弹性中子散射测量了磁振子色散，并将激发模式严格拟合到自旋波模型。磁振子谱可以用一个具有七个最近邻面内交换的面内铁磁海森堡交换模型很好地描述。这个拟合的交换哈密顿量能够对CrSBr的行为进行理论预测：例如，拟合的哈密顿量被用于预测具有自旋轨道增强的CrSBr异质结构中手性磁振子边缘模式的存在。
