Resonant condition of unitary dendritic structure with overlapping negative permittivity and permeability

We demonstrate that a two-dimensional isotropic left-handed materials (LHMs) can be built based on unitary dendritic structure units. Utilizing parameter design, we theoretically deduce a resonant condition in unitary dendritic structure unit, which provided an overlapping negative permittivity and negative permeability response over a frequency band. Employing microwave transmission and prism refractive index experiments, the medium with dendritic structure exhibits a distinct left-handed effect. The proposed implementation of the dendritic structure opens the possibility of realizing integrative isotropic LHMs, especially for simple chemical prepared infrared or visible frequency LHMs.