Broadband Nonreciprocal Quadrupolarization‐Induced Asymmetric Transmission (Q‐AT) in Plasmonic Nanoparticle Aggregates

Non-reciprocal asymmetric transmission, i.e., the dependence of optical transmittance on the direction of light propagation in the material, can be used in optical isolators or photonic circuits. Broadband asymmetric transmission is observed in near-field coupled aggregates of small plasmonic nanoparticles, even for unpolarized light. Non-reciprocity is demonstrated and, using a phenomenological model, induced electric quadrupole moments are identified as the root cause of the effect. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.