Dirac Fermions in Borophene
Dirac Fermions in Borophene
复制标题
硼烯中的狄拉克费米子
DOI：
10.1103/physrevlett.118.096401
复制
发表时间：
2017-03-02
影响因子：
8.6
通讯作者：
Matsuda, Iwao
中科院分区：
文献类型：
--
作者：
Feng, Baojie;Sugino, Osamu;Matsuda, Iwao
第IV族元素的蜂窝结构可以容纳具有非平凡Berry相的无质量狄拉克费米子。它们的电子应用潜力引起了人们极大的兴趣，并促使人们广泛寻找新的狄拉克材料，特别是单层结构。我们提出了一个详细的研究β（12）片，这是一个硼氢化物结构，可以自发地形成在Ag（111）表面。我们的紧束缚分析表明，β（12）片的晶格可以分解成两个三角形的子晶格的方式类似于蜂窝晶格，从而托管狄拉克锥。此外，每个狄拉克锥可以通过引入代表覆盖层-衬底相互作用的周期性扰动来分裂。这些不寻常的电子结构被角分辨光电子能谱证实，并通过第一性原理计算验证。我们的研究结果表明，单层硼作为一个新的平台，实现新型的高速低功耗器件。
Honeycomb structures of group IV elements can host massless Dirac fermions with nontrivial Berry phases. Their potential for electronic applications has attracted great interest and spurred a broad search for new Dirac materials especially in monolayer structures. We present a detailed investigation of the beta(12) sheet, which is a borophene structure that can form spontaneously on a Ag(111) surface. Our tight-binding analysis revealed that the lattice of the beta(12) sheet could be decomposed into two triangular sublattices in a way similar to that for a honeycomb lattice, thereby hosting Dirac cones. Furthermore, each Dirac cone could be split by introducing periodic perturbations representing overlayer-substrate interactions. These unusual electronic structures were confirmed by angle-resolved photoemission spectroscopy and validated by first-principles calculations. Our results suggest monolayer boron as a new platform for realizing novel high-speed low-dissipation devices.