Liang Kun, Jin Lei, Deng Xuyan, Jiang Ping, Yu Li
School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, China.
School of Science, Beijing University of Posts and Telecommunications, Beijing, China.
Nanophotonics. 2023 Jul 25;12(17):3471-3480. doi: 10.1515/nanoph-2023-0304. eCollection 2023 Aug.
A tunable plexcitonic material that sustains multimode hybridization is highly desirable, which is vital for advanced quantum devices. However, the research about regulations of biexcitons-plasmon coherent states has rarely been reported. Here we apply single-nanoparticle scattering spectroscopy correlative with SEM imaging to identify biexcitons-plasmon interaction in a metal-semiconductor hybrid structure composed of a single Au@Ag nanoparticle, J-aggregates molecules and tungsten disulfide (WS) monolayer. The mode competition within the localized plasmonic hotspots (∼240 nm) is revealed by continuously regulating the J-aggregates spacer. Two distinct anticrossings are observed at both excitons resonances, and large double Rabi splittings (137 meV and 124 meV) are obtained successfully. We establish experimentally that J-aggregates and WS monolayer are responsible for the middle polariton states, while plasmon rarely contributes. Further calculations show that plasmonic nanocavity enables coherent energy exchange with different excitons by providing a highly enhanced localized E-field. In addition, we find that the multimode coupling strengths can be efficiently tuned by changing the cavity morphology and environment temperature, where the tuning spectral accuracy can reach up to 1 nm. Our findings uncover the distinctive properties of biexcitons-plasmon polaritons, suggest an easily obtainable multiqubit states platform, and open up a new way to construct nanoscale photonic devices.
一种能够维持多模杂化的可调谐激子 - 等离子体材料是非常理想的，这对于先进的量子器件至关重要。然而，关于双激子 - 等离子体相干态调控的研究鲜有报道。在此，我们应用与扫描电子显微镜成像相关的单纳米颗粒散射光谱，来识别由单个Au@Ag纳米颗粒、J - 聚集体分子和二硫化钨（WS）单层组成的金属 - 半导体混合结构中的双激子 - 等离子体相互作用。通过连续调节J - 聚集体间隔层，揭示了局域等离子体热点（约240 nm）内的模式竞争。在两个激子共振处均观察到两个明显的反交叉现象，并成功获得了大的双拉比分裂（137 meV和124 meV）。我们通过实验确定J - 聚集体和WS单层负责中间极化子态，而等离子体的贡献很少。进一步的计算表明，等离子体纳米腔通过提供高度增强的局域电场，能够与不同的激子进行相干能量交换。此外，我们发现通过改变腔的形态和环境温度，可以有效地调节多模耦合强度，其中调谐光谱精度可达1 nm。我们的研究结果揭示了双激子 - 等离子体极化子的独特性质，提出了一个易于获得的多量子比特态平台，并为构建纳米级光子器件开辟了一条新途径。
