Lu Yu-Wei, Zhou Wen-Jie, Li Yongyao, Li Runhua, Liu Jing-Feng, Wu Lin, Tan Haishu
School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China.
Science, Mathematics and Technology (SMT), Singapore University of Technology and Design (SUTD), 8 Somapah Road 487372, Singapore, Singapore.
Nanophotonics. 2022 Jun 9;11(14):3307-3317. doi: 10.1515/nanoph-2022-0162. eCollection 2022 Jul.
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.
耗散通常与等离激元相关，会导致退相干，并且一般被认为对量子非线性和纠缠是致命的。然而，与直觉相反的是，通过将一个耗散性等离激元纳米天线引入到一个典型的腔量子电动力学（QED）系统中，我们揭示了原子 - 光子准束缚态（qBS）在混合等离激元 - 光子腔中的广泛存在，这是一种具有异常小衰减的奇异本征态。为了推导原子 - 光子qBS的解析条件，我们通过将相互作用的非耦合腔模与宏观QED相连接，构建了一个态密度的量子化双模模型。通过共振等离激元 - 光子耦合，我们展示了单原子qBS将单光子产生效率提高了一个数量级以上；以及双原子qBS与裸光子腔相比显著增强了自发纠缠的产生。值得注意的是，在实际的等离激元 - 光子腔中可以同时实现这种单原子和多原子qBS，为诸如量子光源、量子计算和量子信息等先进量子技术提供了一个通用平台。
