Engineering Giant Rabi Splitting via Strong Coupling between Localized and Propagating Plasmon Modes on Metal Surface Lattices: Observation of √N Scaling Rule

Abstract

We present a strong coupling system realized by coupling the localized surface plasmon mode in individual silver nanogrooves and propagating surface plasmon modes launched by periodic nanogroove arrays with varied periodicities on a continuous silver medium. When the propagating modes are in resonance with the localized mode, we observe a √N scaling of Rabi splitting energy, where N is the number of propagating modes coupled to the localized mode. Here, we confirm a giant Rabi splitting on the order of 450–660 meV (N = 2) in the visible spectral range, and the corresponding coupling strength is 160–235 meV. In some of the strong coupling cases studied by us, the coupling strength is about 10% of the mode energy, reaching the ultrastrong coupling regime.

Tuning of Two-Dimensional Plasmon–Exciton Coupling in Full Parameter Space: A Polaritonic Non-Hermitian System

“…In the reflectance measurement, incident light at certain angle and frequency can be coupled into SPPs with the dispersion relation defined by the grating equation for a specific grating pitch and these SPPs can be out-coupled into the free space. The detailed analysis can be found in our recently published papers using all-metal plasmonic metasurface structures. − It is worth noting that strong coupling observed in ref is due to the interaction between localized LSPR and propagating SPP plasmon modes on metal surface lattices. At zero detuning, the reflectance dips of upper and lower plasmon–exciton polariton modes are symmetric in intensity and they are very sensitive to the detuning condition (see Supporting Information section S5).…”

Second Harmonic Generation Covering the Entire Visible Range from a 2D Material–Plasmon Hybrid Metasurface

“…In this work, we chose 630 nm as an average value for broadband enhancement. However, the strong coupling between LSPR at 630 nm and SPP can greatly modify the resonance peak and weaken the enhancement, [ 48,49 ] see Figure S2b‐d in the Supporting Information. In the future, to eliminate this effect, the pitch and groove depth should change simultaneously (doubly chirped).…”

Dynamic Control of Quantum Emitters Strongly Coupled to the Isolated Plasmon Cavity by the Microfluidic Device

“…Strong coupling between quantum emitters and a single-mode field attracts numerous attention in the quantum science community, − which is not only essential in studying profound quantum optical effects such as quantum entanglement, , vacuum Rabi oscillations, photon blockade, and Bose–Einstein condensates but also crucial for the achievement of advanced quantum optical circuits and quantum information processing. − Strong light–matter interaction occurs when an electronic transition in the matter and a cavity photon are spectral and spatially overlapping . The rate of coherent energy exchange between the two components would exceed other competing decoherence or intrinsic dissipation rates, leading to photon–exciton hybridization and the formation of new quasiparticles with an energy separation recognized as Rabi splitting.…”

“…Strong coupling between quantum emitters and a single-mode field attracts numerous attention in the quantum science community, 1−5 which is not only essential in studying profound quantum optical effects such as quantum entanglement, 6,7 vacuum Rabi oscillations, 8 photon blockade, 9 and Bose−Einstein condensates 10 but also crucial for the achievement of advanced quantum optical circuits and quantum information processing. 11−14 Strong light−matter interaction occurs when an electronic transition in the matter and a cavity photon are spectral and spatially overlapping.…”