Superluminal tunneling of microwaves in smoothly varying transmission lines

TL;DR

This paper investigates superluminal microwave tunneling in transmission lines with inhomogeneous dielectric profiles, revealing reflectionless tunneling phenomena and proposing an experimental test for these effects.

Contribution

It introduces the concept of superluminal tunneling in smoothly varying dielectric transmission lines with positive permittivity, expanding understanding beyond standard wave barriers.

Findings

Reflectionless superluminal tunneling occurs for finite spectral width waves

Inhomogeneous dielectric profiles enable tunneling without reflection

Experimental setup proposed to test superluminal tunneling effects

Abstract

Tunneling of microwaves through a smooth barrier in a transmission line is considered. In contrast to standard wave barriers, we study the case where the dielectric permittivity is positive, and the barrier is caused by the inhomogeneous dielectric profile. It is found that reflectionless, superluminal tunneling can take place for waves with a finite spectral width. The consequences of these findings are discussed, and an experimental setup testing our predictions is proposed.