Lian Chao, Hu Shi-Qi, Zhang Jin, Cheng Cai, Yuan Zhe, Gao Shiwu, Meng Sheng
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Phys Rev Lett. 2020 Sep 11;125(11):116802. doi: 10.1103/PhysRevLett.125.116802.
The past decade has witnessed numerous discoveries of two-dimensional (2D) semimetals and insulators, whereas 2D metals were rarely identified. Borophene, a monolayer boron sheet, has recently emerged as a perfect 2D metal with unique electronic properties. Here we study collective excitations in borophene, which exhibit two major plasmon modes with low damping rates extending from the infrared to ultraviolet regime. The anisotropic 1D plasmon originates from electronic transitions of tilted Dirac cones in borophene, analogous to that in extreme doped graphene. These features enable borophene as an integrated platform of 1D, 2D, and Dirac plasmons, promising for directional polariton transport and broadband optical communication in next-generation optoelectronic devices.
在过去十年中，二维（2D）半金属和绝缘体有众多发现，而二维金属却鲜有被识别的。硼烯，一种单层硼片，最近作为一种具有独特电子特性的完美二维金属出现。在此，我们研究硼烯中的集体激发，其呈现出两种主要的等离激元模式，具有从红外到紫外波段的低阻尼率。各向异性的一维等离激元源于硼烯中倾斜狄拉克锥的电子跃迁，类似于极重掺杂石墨烯中的情况。这些特性使硼烯成为一维、二维和狄拉克等离激元的集成平台，有望用于下一代光电器件中的定向极化激元传输和宽带光通信。
