CrBr₂和CrI₂中链内与链间竞争相互作用产生的螺旋磁性
Helimagnetism from competing intra- and interchain interactions in CrBr$_2$ and CrI$_2$
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中文总结 AI 辅助
该研究针对CrBr₂和CrI₂螺旋磁序的成因，通过非弹性中子散射确定其交换相互作用，发现螺旋磁序源于链内与链间近邻反铁磁相互作用的竞争，还探究了单离子各向异性及温度对磁序的影响。
中文摘要 AI 辅助
CrBr₂和CrI₂是研究维度对磁序影响的有前景平台，它们以体块晶体、单层、封装在碳纳米管中的单链形式分别被分离为三维、二维、一维结构。然而，导致其螺旋磁序的相互作用尚不明确。通过对单晶的非弹性中子散射，我们从自旋波色散确定了这些化合物的交换相互作用，发现螺旋磁序主要源于链内与链间近邻反铁磁相互作用的竞争。单离子各向异性显著，可调控螺旋自旋旋转并在分支交叉点产生非弹性强度的能隙。随着温度升高，长程序消失，但层内关联至少在50 K时仍可检测到。
英文摘要
CrBr$_2$ and CrI$_2$ are promising platforms for studying the effect of dimensionality on magnetic order, having been isolated in a 3-, 2-, and 1-dimensional form as bulk crystals, monolayers, and individual chains encapsulated in carbon nanotubes. However, the interactions that give rise to their helimagnetic order are unknown. Via inelastic neutron scattering on single crystals, we have determined the exchange interactions of these compounds from the spin wave dispersions, finding that the helimagnetic order arises primarily from competing antiferromagnetic interactions between intrachain and interchain nearest-neighbors. Single-ion anisotropy is substantial, modulating the helical spin rotation and gapping the inelastic intensity at points of branch crossings. As temperature increases, long-range order vanishes but intralayer correlations remain detectable up to at least 50 K.
