Electromagnetic tunneling through a single-negative slab paired with a double-positive bi-layer

TL;DR

This paper demonstrates that electromagnetic waves can resonantly tunnel through a structure combining a single-negative slab with a double-positive bi-layer, enabling novel wave manipulation and material synthesis.

Contribution

It introduces a new resonant tunneling phenomenon involving a single-negative slab paired with a double-positive bi-layer, including the possibility of using vacuum and extreme permittivity/permeability values.

Findings

Resonant tunneling occurs through the three-layer structure.

Double-positive slabs can mimic single-negative wave-impedance properties.

The phenomenon is effective over a moderate frequency range.

Abstract

We show that resonant tunneling of electromagnetic fields can occur through a three-layer structure composed of a single-negative (i.e., either negative-permittivity or negative-permeability) slab paired with bi-layer made of double-positive (i.e., positive permittivity and permeability) media. In particular, one of the two double-positive media can be chosen arbitrarily (even vacuum), while the other may exhibit extreme (either near-zero or very high) permittivity/permeability values. Our results on this counterintuitive tunneling phenomenon also demonstrate the possibility of synthesizing double-positive slabs that effectively exhibit single-negative-like wave-impedance properties within a moderately wide frequency range.