Very closely spaced atoms and molecules in the environment around us are constantly interacting, attracting, and repelling each other. Such interactions ultimately enable several phenomena in nature, such as the sticky pads on gecko's feet, as well as photosynthesis. These interactions are governed by a fundamental phenomenon called the dipole-dipole interactions (DDIs). Range of such interactions are limited to very short distances of few tens of nanometers in free space. Increasing the range of such interactions have potential implications in quantum computing and information processing. Additionally, it will also directs the development of photonic devices for optical information processing.
\nResearchers here address this outstanding challenge extend the range of these microscopic interactions to much greater lengths. Through this NSF project, researchers developed special nanostructured materials that enable light to flow through unique angle-dependent paths (called K-Surface Engineering). Theoretical and computational tools to realize such nanostructure material platforms were developed. This project further utilized these tools to perform proof-of-principle experimental demonstrations. The major accomplishments of this project are described below:
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- In hyperbolic media, the dipole-dipole coupling exhibits a remarkable singularity known as super-Coulombic interaction. Unlike traditional DDIs, this super-Coulombic interaction does not depend on the physical distance between particles. Instead, it is determined by an effective interaction distance that approaches zero under ideal conditions. This discovery opens new possibilities for understanding DDIs in hyperbolic media, where the range of these interactions is significantly amplified. To support our findings, we propose several platforms that can experimentally verify this predicted effect. These platforms include using phonon-polaritonic hexagonal boron nitride, plasmonic super-lattices, and hyperbolic meta-surfaces. In our experiments, we found that the interactions were only limited by the absorption and finite size effects of the metamaterial constituents. This suggests that the metamaterials effectively curtail the weakening of interactions over larger distances. These findings highlight the transformative potential of metamaterials in manipulating and controlling DDIs. This knowledge opens new avenues for the design and development of advanced technologies in fields of quantum information processing, communication systems, and sensing applications. Overall, our research sheds light on a previously unknown aspect of DDIs, revealing their intriguing behavior in hyperbolic materials. \n
- The spontaneous emission of quantum emitters can be enhanced by increasing the local density of optical states, while engineering DDIs requires modifications to the two-point spectral density function. In our experiment, we have successfully demonstrated long-range DDIs mediated by surface lattice resonances in a plasmonic nanoparticle lattice. To investigate these interactions, we employed angle-resolved spectral measurements and fluorescence lifetime studies. Our findings reveal that unique nanophotonic modes play a crucial role in mediating long-range DDIs between donor and acceptor molecules. Notably, we observed significant and persistent strengths of the DDIs for a range of densities. The distances between the donor and acceptor dipoles in our experiment corresponded to an average nearest-neighbor separation distance of approximately 800 nm, which is approximately 100 times larger than that in free space. This implies that our approach allows for the engineering and control of long-range DDIs between an ensemble of emitters, even at room temperature. These results have important implications for the field of quantum optics and the design of future devices. By harnessing surface lattice resonances in plasmonic nanoparticle lattices, we can manipulate DDIs over extended distances. This opens up exciting possibilities for applications such as efficient energy transfer, quantum information processing, and the development of novel nanophotonic devices. \n
- In the context of long-range DDIs, the dimensionality of the system plays a crucial role. In our research, we have demonstrated how a resonant nanophotonic structure can modify the apparent dimensionality in an ensemble of interacting emitters, as evidenced by the dynamics of population decay. By studying a dense ensemble of interacting quantum emitters within a resonant nanophotonic structure, we performed measurements that reveale an effective dimensionality reduction to a lower dimension. It is important to note that these emitters were distributed in a three-dimensional (3D) space. This contrasts with the situation in a homogeneous environment, where the apparent dimensionality remains 3D. Our findings present an exciting opportunity to manipulate dimensionality in an ensemble of interacting emitters. The resonant nanophotonic structure enables the modification of the effective dimensionality, providing means to control and engineer the behavior of the emitters. This has implications for various fields, such as quantum information processing, where the dimensionality of the system can significantly impact the performance and functionality of quantum devices. \n
In summary, our work highlights the capability of nanophotonic structures in engineering the interaction between emitters. This opens up new avenues for exploring and harnessing long-range interactions of quantum emitters, offering promising opportunities for advancements in a range of scientific and technological applications.
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\n\t\t\t\t \tLast Modified: 08/02/2023
\n\t\t\t\t\tModified by: Zubin Jacob
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![\"Reducing](\"/por/images/Reports/POR/2023/1654676/1654676_10466475_1687813547968_nsf-3--rgov-66x44.jpg\")
\n\n\nThe image describes the concept and experimental demonstration of reducing the apparent dimension of interacting emitters using a nanostructured plasmonic lattice\nAshwin K Boddeti\nCopyrighted\nZubin Jacob\nReducing dimension using nanostructured media\n \n - \n
![\"Long-range](\"/por/images/Reports/POR/2023/1654676/1654676_10466475_1687813416934_nsf-2--rgov-66x44.jpg\")
\n\n\nthe image describes the computational and experimental demonstration of long-range interactions between emitters mediated by the nanostructured plasmonic lattice\nAshwin K. Boddeti\nCopyrighted\nZubin Jacob\nLong-range Dipole-Dipole Interaction in Plasmonic Lattice\n \n - \n
![\"Super-Coulombic](\"/por/images/Reports/POR/2023/1654676/1654676_10466475_1687813325330_nsf-1--rgov-66x44.jpg\")
\n\n\nThe image describes the experimental and theoretical work demonstrating super-Coulombic type long-range interactions\nCris Cortes, Ward Newman, Zubin Jacob\nCopyrighted\nZubin Jacob\nSuper-Coulombic Interaction in Hyperbolic Metamaterials\n \n
![\"Reducing](\"/por/images/Reports/POR/2023/1654676/1654676_10466475_1687813547968_nsf-3--rgov-214x142.jpg\")
![\"Long-range](\"/por/images/Reports/POR/2023/1654676/1654676_10466475_1687813416934_nsf-2--rgov-214x142.jpg\")
![\"Super-Coulombic](\"/por/images/Reports/POR/2023/1654676/1654676_10466475_1687813325330_nsf-1--rgov-214x142.jpg\")