Using group-theoretical approach, we found a family of four nine-parameter quantum states for the two-spin-1/2 Heisenberg system in an external magnetic field and with multiple components of Dzyaloshinsky–Moriya (DM) and Kaplan–Shekhtman–Entin–Wohlman–Aharony (KSEA) interactions. Exact analytical formulas are derived for the entanglement of formation for the quantum states found. The influence of DM and KSEA interactions on the behavior of entanglement and on the shape of disentangled region is studied. A connection between the two-qubit quantum states and the reduced density matrices of many-particle systems is discussed.

中文翻译：

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具有多元DM和KSEA相互作用的各向异性Heisenberg模型中的量子纠缠。

使用群论方法，我们在外部磁场中发现了两个自旋1/2海森堡系统的四个九参数量子态家族，其中包含Dzyaloshinsky-Moriya（DM）和Kaplan-Shekhtman-Entin的多个分量–Wohlman–Aharony（KSEA）交互。得出了关于所发现的量子态的形成纠缠的精确解析公式。研究了DM和KSEA相互作用对纠缠行为和解缠区域形状的影响。讨论了两个量子位的量子态与多粒子系统的密度降低矩阵之间的联系。