  The self-assembly of metallic colloidal clusters (so called plasmonic
metamolecules) has been viewed as a versatile, but highly effective approach
for the materialization of the metamaterials exhibiting artificial magnetism at
optical frequencies (including visible and near infrared (NIR) regimes).
Indeed, several proofs of concepts of plasmonic metamolecules have been
successfully demonstrated in both theoretical and experimental ways.
Nevertheless, this self-assembly strategy has barely been used and still
remains an underutilized method. For example, the self-assembly and optical
utilization of the plasmonic metamolecules have been limited to the discrete
unit of the structure; the materialization of effective optical medium made of
plasmonic metamolecules is highly challenging. In this work, we theoretically
exploited the practical limits of self-assembly technology for the fabrication
of optical magnetic metamaterials.
