Plasmonic Anti-Hermitian Coupling for Controlling Light at the Nanoscale
  Open quantum systems consisting of coupled bound and continuum states have been studied in a variety of physical systems, particularly within the scope of nuclear, atomic and molecular physics. In the open systems, the effects of the continuum decay channels are accounted for by indirect non-Hermitian couplings among the quasi-bound states. Here we explore anti-Hermitian coupling in a plasmonic system for spatially manipulating light on the nano-scale. We show that by utilizing the anti-Hermitian coupling, plasmonic antennas closely packed within only {\lambda}/15 separations can be individually excited from the far field, which are otherwise indistinguishable from each other. 
Shuang Zhang, Ziliang Ye, Yuang Wang, Yong-shik Park, Guy Bartal,   Michael Mrejen, Xiaobo Yin, Xiang Zhang
physics.optics