Negative permittivity from positive polarizability in metamaterials
Year: 2026
Type: article
Abstract: We present a Clausius-Mossotti analysis of effective-permittivity sign reversal in a dilute array of metamaterial meta-atoms with an inductor–capacitor (LC) resonance. The meta-atoms are approximated as polarizable electric point dipoles, and the effective permittivity is obtained from the classical Lorentz local-field relation. This model shows that negative effective permittivity does not necessarily require the polarizability of an individual meta-atom to be negative. Instead, a resonantly enhanced positive polarizability can drive the polarizability density through the Clausius-Mossotti pole and produce a pre-resonant frequency interval in which the meta-atom polarizability remains positive while the effective permittivity becomes negative. This interval lies below the isolated LC resonance and is therefore distinct from the more familiar post-resonant regime associated with oscillator phase reversal. Including damping shows that the pre-resonant branch survives finite loss. The analysis clarifies the collective origin of the sign reversal within the classical point-dipole picture and provides a compact analytic reference for epsilon-negative behavior in resonant metamaterials. In practical structures, absorption, radiation damping, finite size, anisotropy, and inter-cell near-field coupling are expected to smooth or shift the idealized features.
Source: EPJ Applied Metamaterials
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $565
OpenAlex ID: W7214345736