Dissipation, often associated with plasmons, leads to decoherence and is generally considered fatal for quantum nonlinearities and entanglement. Counterintuitively, by introducing a dissipative plasmonic nanoantenna into a typical cavity quantum electrodynamics (QED) system, we unveil the wide existence of the atom‐photon quasi‐bound state (qBS), a kind of exotic eigenstate with anomalously small decay, in the hybrid plasmonic‐photonic cavity. To derive the analytical condition of atom‐photon qBS, we formulate a quantized two‐mode model of the local density of states by connecting the interacting uncoupled cavity modes to the macroscopic QED. With resonant plasmon‐photon coupling, we showcase the single‐atom qBS that improves the efficiency of single‐photon generation over one order of magnitude; and the two‐atom qBS that significantly enhances spontaneous entanglement generation compared with a bare photonic cavity. Notably, such single‐atom and multi‐atom qBS can be simultaneously accessed in realistic plasmonic‐photonic cavities, providing a versatile platform for advanced quantum technologies, such as quantum light sources, quantum computation, and quantum information.

Medical image fusion has become a hot biomedical image processing technology in recent years. The technology coalesces useful information from different modal medical images onto an informative single fused image to provide reasonable and effective medical assistance. Currently, research has mainly focused on dual-modal medical image fusion, and little attention has been paid on trimodal medical image fusion, which has greater application requirements and clinical significance. For this, the study proposes an end-to-end generative adversarial network for trimodal medical image fusion. Utilizing a multi-scale squeeze and excitation reasoning attention network, the proposed method generates an energy map for each source image, facilitating efficient trimodal medical image fusion under the guidance of an energy ratio fusion strategy. To obtain the global semantic information, we introduced squeeze and excitation reasoning attention blocks and enhanced the global feature by primitive relationship reasoning. Through extensive fusion experiments, we demonstrate that our method yields superior visual results and objective evaluation metric scores compared to state-of-the-art fusion methods. Furthermore, the proposed method also obtained the best accuracy in the glioma segmentation experiment. The code is publicly available at https://github.com/JasonWong30/PRRGAN.

We investigate the single-photon blockade (1PB) in the quasichiral regime of atom–photon interaction, where the effective coupling between the cavity and the atom is bidirectional but asymmetrical, achieved by coupling to a dissipative environment. A synthetic magnetic current ϕ is induced in the closed-loop coupling, which breaks down the reciprocity of atom–photon interaction, and can be utilized to create asymmetrical or even unidirectional effective coupling between two selected quantum states. As an example, we couple the single-atom cavity quantum electrodynamics (QED) system to a strongly dissipative plasmonic cavity. We find that in the quasichiral regime, the unconventional photon blockade (UPB) and the conventional photon blockade (CPB) realize simultaneously in the condition of maximum chirality (ϕ = π/2 and 3π/2). As a result, 1PB in the quasichiral regime can combine the advantages of both UPB and CPB, demonstrating the perfect single-photon purity, higher efficiency, non-oscillating time dynamics as well as lower requirement of mode coupling to achieve UPB. Our work paves the way for 1PB towards practical applications and reveals the intriguing quantum-optics phenomena in the quasichiral light–matter interaction.