Magnetic order in XY-type antiferromagnetic monolayer CoPS3 revealed by Raman spectroscopy
Magnetic order in XY-type antiferromagnetic monolayer CoPS3 revealed by Raman spectroscopy
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DOI：
10.1103/physrevb.103.235411
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发表时间：
2021-06-07
影响因子：
3.7
通讯作者：
Dai, Jun-Feng
中科院分区：
文献类型：
--
作者：
Liu, Qiye;Wang, Le;Dai, Jun-Feng
Mermin-Wagner-Coleman 定理预测，在二维 (2D) 各向同性系统中，有限温度下不存在长程磁序，但它确实预测了平面磁体在 Kosterlitz-Thouless (KT) 转变处具有发散相关长度的准长程序。作为二维平面反铁磁体的代表，单层 CoPS3 有望成为最终薄型自旋电子学的单层反铁磁平台。在这里，借助对局部磁序敏感的磁致伸缩，我们观察到单层 CoPS3 中低于 T-KT 的特征声子模式分裂。单层磁振子信号显示了相关的磁转变。它表示 KT 相变以下的精确二维平面自旋模型中的准长程有序。表征二维行为的层间和层内相互作用之间的比率 (J'/J) 估计约为 0.03。我们的结果提供了一种有效的方法来检测二维磁体中低至单层极限的准长程反铁磁有序性。
Mermin-Wagner-Coleman theorem predicts no long-range magnetic order at finite temperature in the two-dimensional (2D) isotropic systems, but it does predict a quasi-long-range order with a divergent correlation length at the Kosterlitz-Thouless (KT) transition for planar magnets. As a representative of two-dimensional planar antiferromagnets, single-layer CoPS3 carries the promise of monolayer antiferromagnetic platforms for the ultimately thin spintronics. Here, with the aid of magnetostriction which is sensitive to the local magnetic order, we observe the signature phonon mode splitting of below T-KT in monolayer CoPS3. The two-magnon signal in the monolayer one manifests the associated magnetic transition. It indicates the quasi-long-range order in an exact 2D planar spin model below KT phase transition. The ratio (J'/J) between the interlayer and intralayer interactions, which characterizes the 2D behaviors, is evaluated to be around 0.03. Our results provide an efficient method to detect the quasi-long-range antiferromagnetic ordering in the two-dimensional magnets down to the monolayer limit.