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arXiv · 2304.12897

Non-Hermitian Waveguide Cavity QED with Tunable Atomic Mirrors

Wei Nie·Tao Shi·Yu-xi Liu·Franco Nori
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Abstract

Optical mirrors determine cavity properties by means of light reflection. Imperfect reflection gives rise to open cavities with photon loss. We study an open cavity made of atom-dimer mirrors with a tunable reflection spectrum. We find that the atomic cavity shows anti-$\mathcal{PT}$ symmetry. The anti-$\mathcal{PT}$ phase transition controlled by atomic couplings in mirrors indicates the emergence of two degenerate cavity supermodes. Interestingly, a threshold of mirror reflection is identified for realizing strong coherent cavity-atom coupling. This reflection threshold reveals the criterion of atomic mirrors to produce a good cavity. Moreover, cavity quantum electrodynamics with a probe atom shows mirror-tuned properties, including reflection-dependent polaritons formed by the cavity and probe atom. Our work presents a non-Hermitian theory of an anti-$\mathcal{PT}$ atomic cavity, which may have applications in quantum optics and quantum computation.

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Wei Nie, Tao Shi, Yu-xi Liu, Franco Nori. 2023-09-12. Non-Hermitian Waveguide Cavity QED with Tunable Atomic Mirrors. https://doi.org/10.1103/physrevlett.131.103602

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