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arXiv · 2202.08076

Bimorphic Floquet Topological Insulators

Georgios G. Pyrialakos·Julius Beck·Matthias Heinrich·Lukas J. Maczewsky·Nikolaos V. Kantartzis·Mercedeh Khajavikhan·Alexander Szameit·Demetrios N. Christodoulides
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Abstract

Topological theories have established a new set of rules that govern the transport properties in a wide variety of wave-mechanical settings. In a marked departure from the established approaches that induce Floquet topological phases by specifically tailored discrete coupling protocols or helical lattice motions, we introduce a new class of bimorphic Floquet topological insulators that leverage connective chains with periodically modulated on-site potentials to unlock new topological features in the system. In exploring a 'chain-driven' generalization of the archetypical Floquet honeycomb lattice, we identify a rich phase structure that can host multiple non-trivial topological phases associated simultaneously with both Chern-type and anomalous chiral states. Experiments carried out in photonic waveguide lattices reveal a unique and strongly confined helical edge state that, owing to its origin in bulk flat bands, can be set into motion in a topologically protected fashion, or halted at will, without compromising its adherence to individual lattice sites.

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Georgios G. Pyrialakos, Julius Beck, Matthias Heinrich, Lukas J. Maczewsky, Nikolaos V. Kantartzis, Mercedeh Khajavikhan, Alexander Szameit, Demetrios N. Christodoulides. 2022-02-16. Bimorphic Floquet Topological Insulators. https://doi.org/10.1038/s41563-022-01238-w

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