Electrostatic theory for designing lossless negative permittivity metamaterials.

We develop an electrostatic theory for designing bulk composites with effective lossless negative permittivities. The theory and associated design procedure are validated by comparing their predictions with those of rigorous full-wave simulations. It is demonstrated that the excitation of the Fröhlich mode (the first-order surface mode) of the constitutive nanoparticles plays a key role in achieving negative permittivities with compensated losses.