Frustration and Atomic Ordering in a Monolayer Semiconductor Alloy
Frustration and Atomic Ordering in a Monolayer Semiconductor Alloy
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DOI：
10.1103/physrevlett.124.096101
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发表时间：
2020-03-05
影响因子：
8.6
通讯作者：
Zettl, Alex
中科院分区：
文献类型：
--
作者：
Azizi, Amin;Dogan, Mehmet;Zettl, Alex
受抑的相互作用可以导致由基本物理量与底层晶格的不相容相互作用引起的短程有序。最简单的例子是具有反铁磁相互作用的自旋三角晶格，其中最近邻自旋-自旋相互作用不能同时被能量最小化。在这里，我们表明，工程挫折的相互作用是一个可能的路线控制半导体合金的结构和电子现象。使用像差校正扫描透射电子显微镜结合密度泛函理论计算，我们证明了原子有序的二维半导体合金之间的竞争的结果的几何约束和最近邻相互作用。统计分析揭示了晶格中短程有序的存在。此外，我们展示了如何诱导有序可以被用来作为另一个自由度，大大修改单层半导体合金的带隙。
Frustrated interactions can lead to short-range ordering arising from incompatible interactions of fundamental physical quantities with the underlying lattice. The simplest example is the triangular lattice of spins with antiferromagnetic interactions, where the nearest-neighbor spin-spin interactions cannot simultaneously be energy minimized. Here we show that engineering frustrated interactions is a possible route for controlling structural and electronic phenomena in semiconductor alloys. Using aberration-corrected scanning transmission electron microscopy in conjunction with density functional theory calculations, we demonstrate atomic ordering in a two-dimensional semiconductor alloy as a result of the competition between geometrical constraints and nearest-neighbor interactions. Statistical analyses uncover the presence of short-range ordering in the lattice. In addition, we show how the induced ordering can be used as another degree of freedom to considerably modify the band gap of monolayer semiconductor alloys.