MnSb₂Te₄中缺陷诱导的光学磁振子与局域磁关联
Defect-induced optical magnons and local magnetic correlations in MnSb2Te4
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中文总结 AI 辅助
研究针对拓扑磁绝缘体Mn(Bi,Sb)₂Te₄家族的MnSb₂Te₄，通过非弹性中子散射结合半经典自旋动力学模拟，揭示了反位混合诱导的光学磁振子及局域磁关联，明确了线性Mn-Te-Mn键对反位磁缺陷耦合的介导作用。
中文摘要 AI 辅助
磁性缺陷工程为调控量子材料中的磁与电子态提供了途径。在拓扑磁绝缘体Mn(Bi,Sb)₂Te₄家族中，Sb取代会导致Mn与Sb原子的位点混合，进而影响磁有序和能带拓扑。本研究通过对MnSb₂Te₄单晶开展非弹性中子散射，直接探测这些缺陷诱导的磁相互作用。研究发现，反位混合形成不等价且无序的磁亚晶格，其中强缺陷诱导的反铁磁耦合产生了带大能隙的光学磁振子。半经典自旋动力学模拟可准确描述有序态和顺磁态下的磁激发，并确定线性Mn-Te-Mn键介导了与反位磁缺陷的耦合。
英文摘要
Magnetic defect engineering offers a route to manipulate and control magnetic and electronic states in quantum materials. In the Mn(Bi,Sb)2Te4 family of topological magnetic insulators, Sb substitution facilitates site mixing between Mn and Sb atoms that affects magnetic order and band topology. Here we directly probe these defect-induced magnetic interactions using inelastic neutron scattering on single crystals of MnSb2Te4. We find that antisite mixing generates inequivalent and disordered magnetic sublattices where strong defect-induced antiferromagnetic coupling produces an optical magnon with a large gap. Semi-classical spin-dynamics simulations accurately capture magnetic excitations in the ordered and paramagnetic states and identify that linear Mn-Te-Mn bonds mediate coupling to antisite magnetic defects.
