Squeezing electromagnetic energy with a dielectric split ring inside a permeability-near-zero metamaterial

An electromagnetic energy squeezing mechanism is proposed based on the special properties of permeability-near-zero metamaterials. It is found that nearly no energy stream can enter a simply connected conventional dielectric material positioned inside a permeability-near-zero material. When the dielectric domain is shaped as a split ring (with a gap opened) surrounding a source, the electromagnetic energy generated by the source is forced to propagate through the gap. When the gap is narrow, the energy stream density becomes very large and makes the magnetic field enhanced drastically in the gap. The narrow gap can be long and bended. This provides us a method to obtain strong magnetic field without using resonance enhancement.