Photon localisation and Bloch symmetry breaking in luminal gratings

TL;DR

This paper investigates the transition from fluid-like to localized light states in luminal gratings traveling at near-light speeds, revealing symmetry breaking and introducing a new calculation method for this regime.

Contribution

It introduces a novel technique for analyzing luminal gratings and details the symmetry-breaking transition and localized states of light at near-light velocities.

Findings

Observation of symmetry breaking transition at luminal velocities

Identification of localized light states in gratings

Analysis of critical exponents and oscillations in transmitted intensity

Abstract

In gratings travelling at nearly the velocity of light a symmetry breaking transition is observed between free-flowing fluid-like Bloch waves observed at lower grating velocities and, at luminal velocities, condensed, localised states of light captured in each period of the grating and locked to its velocity. We introduce a new technique for calculating in this regime and use it to study the transition in detail shedding light on the critical exponents, and the periodic oscillations in transmitted intensity seen in the pre-transition regime.