I have calculated the dielectric constant of plasma polymerized thin films. For some samples, I have found the negative value of the dielectric constant. Please explain the physical significance of the negative dielectric constant.
The negative effective dielectric constant is a very important key for creating materials with a negative refractive index. For isotropic materials permittivity is a scalar but frequency dependent quantity. Frequency dependence of permittivity is called dispersion. For some materials at certain frequency ranges permittivity can be negative e.g. for plasma at RF frequencies or for metals at infrared frequencies. Negative permittivity means that the electric displacement vector and the electric field vector point in the opposite directions but it does not necessary mean that the electric energy stored is such medium is negative.
Md. Tarek Hossain "The negative effective dielectric constant is a very important key for creating materials with a negative refractive index".
Please explain how it is important?
NASA Langley Research Center has developed a novel negative dielectric constant material based on ion conducting materials. A negative dielectric constant material is an essential key for creating metamaterials, or artificial negative index materials (NIMs). NIMs have generated great attention due to their unique and exotic electromagnetic properties, and could be used for unique optical and microwave applications, including new methods of electromagnetic cloaking and extremely low loss communications.
A negative dielectric constant in nano-particle materials under an electric field at very low frequencies
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