Wu Yingjie, Ou Qingdong, Yin Yuefeng, Li Yun, Ma Weiliang, Yu Wenzhi, Liu Guanyu, Cui Xiaoqiang, Bao Xiaozhi, Duan Jiahua, Álvarez-Pérez Gonzalo, Dai Zhigao, Shabbir Babar, Medhekar Nikhil, Li Xiangping, Li Chang-Ming, Alonso-González Pablo, Bao Qiaoliang
Department of Materials Science and Engineering, and ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Australia.
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China.
Nat Commun. 2020 May 27;11(1):2646. doi: 10.1038/s41467-020-16459-3.
Phonon polaritons (PhPs) have attracted significant interest in the nano-optics communities because of their nanoscale confinement and long lifetimes. Although PhP modification by changing the local dielectric environment has been reported, controlled manipulation of PhPs by direct modification of the polaritonic material itself has remained elusive. Here, chemical switching of PhPs in α-MoO is achieved by engineering the α-MoO crystal through hydrogen intercalation. The intercalation process is non-volatile and recoverable, allowing reversible switching of PhPs while maintaining the long lifetimes. Precise control of the intercalation parameters enables analysis of the intermediate states, in which the needle-like hydrogenated nanostructures functioning as in-plane antennas effectively reflect and launch PhPs and form well-aligned cavities. We further achieve spatially controlled switching of PhPs in selective regions, leading to in-plane heterostructures with various geometries. The intercalation strategy introduced here opens a relatively non-destructive avenue connecting infrared nanophotonics, reconfigurable flat metasurfaces and van der Waals crystals.
声子极化激元（PhPs）因其纳米级限制和长寿命而在纳米光学领域引起了极大的关注。尽管已经报道了通过改变局部介电环境来修饰PhP，但通过直接修饰极化激元材料本身来对PhPs进行可控操纵仍然难以实现。在此，通过氢嵌入对α-MoO晶体进行工程设计，实现了α-MoO中PhPs的化学切换。嵌入过程是非挥发性且可恢复的，能够在保持长寿命的同时对PhPs进行可逆切换。对嵌入参数的精确控制能够分析中间状态，在该状态下，充当平面内天线的针状氢化纳米结构有效地反射和发射PhPs，并形成排列良好的腔。我们进一步在选择性区域实现了PhPs的空间控制切换，从而得到具有各种几何形状的平面内异质结构。这里引入的嵌入策略开辟了一条相对无损的途径，将红外纳米光子学、可重构平面超表面和范德华晶体联系起来。
