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arXiv 2108.02159cond-mat.str-elcond-mat.mes-hall
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过渡金属二硫属化合物云纹材料中的竞争磁态

Competing magnetic states in transition metal dichalcogenide moiré materials

Nai Chao Hu, Allan H. MacDonald

摘要:

小扭转角过渡金属二硫属化物(TMD)异质双层形成孤立的平坦莫尔条纹,其近似由三角晶格广义哈伯德模型[PhysRevLett.121.026402]描述。在这篇文章中,我们将探讨在不同的控制条件下出现的金属态和绝缘态,密度为每个摩尔周期一个电子,以及它们之间的转换。通过结合完全自洽的Hartree-Fock理论计算与原子极限附近的强耦合展开,我们确定了四个不同的磁状态和一个磁状态附近的模型相图的金属-绝缘体相变线。铁磁绝缘状态,稳定的非本地直接交换相互作用,是令人惊讶的突出。

英文摘要:

Small-twist-angle transition metal dichalcogenide (TMD) heterobilayers develop isolated flat moiré bands that are approximately described by triangular lattice generalized Hubbard models [PhysRevLett.121.026402]. In this article we explore the metallic and insulating states that appear under different control conditions at a density of one-electron per moiré period, and the transitions between them. By combining fully self-consistent Hartree-Fock theory calculations with strong-coupling expansions around the atomic limit, we identify four different magnetic states and one nonmagnetic state near the model phase diagram's metal-insulator phase-transition line. Ferromagnetic insulating states, stabilized by non-local direct exchange interactions, are surprisingly prominent.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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