A negative dielectric constant in nano-particle materials under an electric field at very low frequencies

TL;DR

This paper reports the discovery of a large negative dielectric constant in oxide nano-particle aggregates under low-frequency electric fields at room temperature, suggesting potential applications in superconductivity and communications.

Contribution

It presents the first observation of a field-induced negative dielectric constant in nano-particle materials at very low frequencies, proposing a collective effect as the underlying mechanism.

Findings

Negative dielectric constant observed below 1 Hz at room temperature

Induced charge opposes the applied electric field

Potential implications for superconductivity and electromagnetic wave manipulation

Abstract

The significance of a negative dielectric constant has long been recognized. We report here the observation of a field-induced large negative dielectric constant of aggregates of oxide nano-particles at frequencies below ~ 1 Hz at room temperature. The accompanying induced charge detected opposes the electric field applied in the field-induced negative dielectric constant state. A possible collective effect in the nano-particle aggregates is proposed to account for the observations. Materials with a negative dielectric constant are expected to provide an attraction between similar charges and unusual scattering to electromagnetic waves with possible profound implications for high temperature superconductivity and communications.