Understanding the unique characteristics of plexcitons, hybridized states resulting from the strong coupling between plasmons and excitons, is vital for both fundamental studies and practical applications in nano-optics. However, the research of plexcitons from the perspective of chiral optics has been rarely reported. Here, we experimentally investigate the optical chirality of plexcitonic systems consisting of composite metal nanoparticles and chiral J-aggregates in the strong coupling regime. Mode splitting and anticrossing behavior are observed in both the circular dichroism (CD) and extinction spectra of the hybrid nanosystems. A large mode splitting (at zero detuning) of up to 136 meV/214 meV in CD/extinction measurements confirms that the systems attain the strong coupling regime. This phenomenon indicates that the formation of plexcitons modifies not only the extinction but also the optical chirality of the hybrid systems. We develop a quasistatic theory to elucidate the chiral optical responses of hybrid systems. Furthermore, we propose and justify a criterion of strong plasmon–exciton interaction: the mode splitting in the CD spectra (at zero detuning) is larger than half of that in the extinction spectra. Our findings give a chiral perspective on the study of strong plasmon–exciton coupling and have potential applications in the chiral optical field.

The Phanerozoic Eon has witnessed considerable changes in the climate system as well as abundant animals and plant life. Therefore, the evolution of the climate system in this Eon is worthy of extensive research. Only by studying climate changes in the past can we understand the driving mechanisms for climate changes in the future and make reliable climate projections. Apart from observational paleoclimate proxy datasets, climate simulations provide an alternative approach to investigate past climate conditions of the Earth, especially for long time span in the deep past. Here we perform 55 snapshot simulations for the past 540 million years, with a 10-million-year interval, using the Community Earth System Model version 1.2.2 (CESM1.2.2). The climate simulation dataset includes global distributions of monthly surface temperatures and precipitation, with a 1° horizontal resolution of 0.9° × 1.25° in latitude and longitude. This open access climate dataset is useful for multidisciplinary research, such as paleoclimate, geology, geochemistry, and paleontology.

Strong coupling system with plasmons and emitters is an attractive field in the light-matter interaction for the hybrid states combined with the properties of plasmons and emitters. When the emitter are chiral molecules, surface plasmon polaritons (SPPs) provide an excellent research platform which possesses the advantages of chiral field enhancement and electromagnetic wave transmission in the subwavelength size and the chiral strong coupling system has wide applications in optical logic device and biological detection in nanoscale. We experimentally investigate the circular dichroism (CD) of the system with SPPs and chiral J-aggregates from the weak coupling regime to the strong coupling regime. The Rabi splitting of 143.3/154.5 meV, which is a significant phenomenon of the strong coupling can be observed both in the CD and the extinctions. Further experimental results show that, in the strong coupling regime, when the system achieves resonance, the intensity of CD signals corresponding to the upper energy band is stronger than that of the lower energy band, different from the behavior in the extinctions. We develop a method to calculate the dispersion relation in the chiral strong coupling system and explain the extinctions as well as the optical chirality of the hybrid states. The investigation of the CD enriches the characters of hybrid states in the strong coupling system and brings potential applications.

Strong coupling systems enable coherent energy exchange between the light field and material electrons in nanoscale space. Active manipulation of this phenomenon by external stimuli is crucial for advanced...

We theoretically investigate the coupling between a single Ag nanoparticle and chiral molecular J-aggregates (TDBC). The element of the structure is composed of a Ag nanoparticle entirely surrounded by chiral TDBC. The results show that the coupling between the Ag nanoparticle and TDBC can be tuned by the size of the Ag nanoparticle. By changing the size of the Ag nanoparticle, both the strong coupling effect and the weak coupling effect between the Ag nanoparticle and TDBC are achieved. Circular dichroism (CD) spectra of the hybridized structures in both the strong and the weak coupling regimes present a Fano line-shape, which can be represented in the form of . We also find that the CD spectrum in the strong coupling regime is less than that in the weak coupling regime. The maximum of the CD spectrum of the hybridized structure in the scattering spectrum is amplified 130 times compared to that of chiral TDBC in the strong coupling regime, and 490 times compared to that in the weak coupling regime, respectively. Much more energy is used to change the resonant wavelength of the hybridized structure in the strong coupling regime. The radiative efficiency of the system is suppressed. In the weak coupling regime, the energy is mainly used to enhance the CD spectrum. Our research has great potential for molecule detection.