Coupling-Enhanced Broadband Mid-Infrared Light Absorption in Graphene   Plasmonic Nanostructures
  Plasmons in graphene nanostructures show great promise for mid-infrared applications ranging from a few to tens of microns. However, mid-infrared plasmonic resonances in graphene nanostructures are usually weak and narrow-banded, limiting their potential in light manipulation and detection. Here we investigate the coupling among graphene plasmonic nanostructures and further show that by engineering the coupling, enhancement of light-graphene interaction strength and broadening of spectral width can be achieved simultaneously. Leveraging the concept of coupling, we demonstrate a hybrid 2-layer graphene nanoribbon array which shows 5 to 7% extinction within the entire 8 to 14 {\mu}m (~700 to 1250 cm-1) wavelength range, covering one of the important atmosphere "infrared transmission windows". Such coupled hybrid graphene plasmonic nanostructures may find applications in infrared sensing and free-space communications. 
Bingchen Deng, Qiushi Guo, Cheng Li, Haozhe Wang, Xi Ling, Damon B.   Farmer, Shu-jen Han, Jing Kong, Fengnian Xia
cond-mat.mes-hall