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arXiv · 2606.01146

Most Subradiant Bound Photon Pairs from Chirality-Mediated Dispersion Softening

Kailin Tan·Xuanbing Jiang·Dong Wang·Saijun Wu
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Abstract

We study the subradiant bound states (BSs) in a two-level atom array chirally coupled to a one-dimensional waveguide. We demonstrate that the chiral interaction can drive BSs to become the most subradiant two-excitation states across a wide spacing range. This phenomenon is rooted in a mechanism of chirality-mediated dispersion softening, where the BS band distortion suppresses the band curvature $|\alpha_2|$ at an extremum point. We rigorously prove that the BS decay rate follows the scaling $\Gamma \sim |\alpha_2|/N^3$, revealing that the reduction of $|\alpha_2|$ is key to suppressing emission and enhancing subradiance. We also show the existence of chiral BSs in a realistic nanofiber interface.

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Kailin Tan, Xuanbing Jiang, Dong Wang, Saijun Wu. 2026-05-31. Most Subradiant Bound Photon Pairs from Chirality-Mediated Dispersion Softening. https://arxiv.org/abs/2606.01146

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