Broadband epsilon-near-zero composites made of metal nanospheroids

We use a homogenization technique to estimate the efficiency of the real part of the effective permittivity nulling for suspensions of randomly oriented metal spheroids in terms of bandwidth and dielectric losses. The design of broadband epsilon-near-zero metamaterials have been demonstrated through the solution of an inverse problem. Manyfold solution branches for extracted geometrical parameters have been predicted, their origin has been explained, and the behavior of losses has been briefly considered. Realizability of metamaterials with the extracted parameters has been discussed in terms of aspect ratio and size of spheroids, and their promise for high broadband absorption has been demonstrated.