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arXiv · 2110.10070

A non-Hermitian optical atomic mirror

Yi-Cheng Wang·Jhih-Shih You·H. H. Jen
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Abstract

Explorations of symmetry and topology have led to important breakthroughs in quantum optics, but much richer behaviors arise from the non-Hermitian nature of light-matter interactions. A high-reflectivity, non-Hermitian optical mirror can be realized by a two-dimensional subwavelength array of neutral atoms near the cooperative resonance associated with the collective dipole modes. Here we show that exceptional points develop from a nondefective degeneracy by lowering the crystal symmetry of a square atomic lattice, and dispersive bulk Fermi arcs that originate from exceptional points are truncated by the light cone. We also find, although the dipole-dipole interaction is reciprocal, the geometry-dependent non-Hermitian skin effect emerges. Furthermore, skin modes localized at a boundary show a scale-free behavior that stems from the long-range interaction and whose mechanism goes beyond the framework of non-Bloch band theory. Our work opens the door to the study of the interplay among non-Hermiticity, topology, and long-range interaction.

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quant-phcond-mat.quant-gasphysics.atom-phphysics.optics

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Yi-Cheng Wang, Jhih-Shih You, H. H. Jen. 2021-10-19. A non-Hermitian optical atomic mirror. https://doi.org/10.1038/s41467-022-32372-3

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