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arXiv · 1707.02687

Robust Edge States in Amorphous Gyromagnetic Photonic Lattices

Shampy Mansha·Y. D. Chong
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Abstract

We numerically study amorphous analogues of a two-dimensional photonic Chern insulator. The amorphous lattices consist of gyromagnetic rods that break time-reversal symmetry, with the lattice sites generated by a close-packing algorithm. The level of short-range order is adjustable, and there is no long-range order. The topologically nontrivial gaps of the photonic Chern insulator are found to persist into the amorphous regime, so long as there is sufficient short-range order. Strongly nonreciprocal robust transmission occurs via edge states, which are shown to propagate ballistically despite the absence of long-range order, and to be exponentially localized along the lattice edge. Interestingly, there is an enhancement of nonreciprocal transmission even at very low levels of short-range order, where there are no discernable spectral gaps.

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Shampy Mansha, Y. D. Chong. 2017-09-04. Robust Edge States in Amorphous Gyromagnetic Photonic Lattices. https://doi.org/10.1103/physrevb.96.121405

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