Topological photonic crystal with equifrequency Weyl points

TL;DR

This paper demonstrates that four equifrequency Weyl points can be realized in time-reversal invariant photonic crystals, with potential applications in imaging, cloaking, and selectivity, supported by symmetry analysis and band-structure calculations.

Contribution

It introduces a minimal configuration of four equifrequency Weyl points in photonic crystals and proposes a feasible modification of double-gyroid structures to realize them.

Findings

Four equifrequency Weyl points can be achieved in time-reversal invariant photonic crystals.

Proposed modification of double-gyroid photonic crystals to realize Weyl points.

Photonic crystals with Weyl points have applications in imaging and cloaking.

Abstract

Weyl points in three-dimensional photonic crystals behave as monopoles of Berry flux in momentum space. Here, based on general symmetry analysis, we show that a minimal number of four symmetry-related (consequently equifrequency) Weyl points can be realized in time-reversal invariant photonic crystals. We further propose an experimentally-feasible way to modify double-gyroid photonic crystals to realize four equifrequency Weyl points, which is explicitly confirmed by our first-principle photonic band-structure calculations. Remarkably, photonic crystals with equifrequency Weyl points are qualitatively advantageous in applications including angular selectivity, frequency selectivity, invisibility cloaking, and three dimensional imaging.