On photonic tunnelling and the possibility of superluminal transport of electromagnetic energy

TL;DR

This paper revisits a Lorentz-invariant theory explaining superluminal light propagation in waveguides, demonstrating conditions under which electromagnetic energy can locally travel faster than light without violating relativity.

Contribution

It applies the Harish-Chandra formalism to electromagnetic energy transport, proving superluminal velocities are possible in nonabsorptive, nondispersive waveguides, and validates this within quantum electrodynamics.

Findings

Superluminal average velocity of electromagnetic energy in waveguides.

Validation within quantum electrodynamics framework.

Conditions for designing superluminal optical devices.

Abstract

Motivated by increased interest in experiments in which light appears to propagate by tunnelling at superluminal velocity, the Lorentz invariant theory proposed by Partha Ghose to explain these surprising effects is revisited. This theory is based on the Harish-Chandra formalism, which describes the relativistic dynamics of a massless spin-1 boson, like a photon. Via this formalism, the Bohmian average transport velocity of the electromagnetic energy is formulated. It is proved that, if the dielectric making the waveguide is nonabsorptive and nondispersive, this velocity can be superluminal. This result is validated in the framework of quantum electrodynamics, demonstrating that the average velocity of the photon inside the waveguide is given by the contribution of instantaneous superluminal velocities. This theory, therefore, suggests the optimal conditions for designing optical devices capable of locally transporting electromagnetic energy at superluminal velocities mitigating the signal attenuation.