Periodic Reporting for period 3 - NZINATECH (Near-zero-index nanophotonic technologies)
Reporting period: 2024-01-01 to 2025-06-30
Near-zero-index (NZI) media is a family of photonic nanostructures (continuous media and/or metamaterials) characterized by a near-zero refractive index. As the refractive index approaches zero, spatial and temporal variations of the electromagnetic field decouple, giving rise of a regime of qualitatively different light-matter interactions. Therefore, NZI nanostructures exhibit a unique optical response, where a concept as basic as the geometry plays an essentially different role. Examples of the exotic wave phenomena include transmission through deformed waveguides, cavities whose resonant frequency does not depend on the geometry of their external boundary, nonradiating modes in three-dimensional open cavities, violation of effective medium theories, anomalous dispersion, nonperturbative nonlinear optics, to name a few.
These unconventional effects have a high potential for technological innovation. However, the crucial challenge of transforming these basic phenomena into practical devices has not yet been addressed. In NZINATECH, we are addressing this challenge by pushing forward the basic theoretical research on NZI media to the stage of NZI nanophotonic technologies. To this end, we are carrying out an ambitious research plan that includes the experimental demonstration of NZI devices in different material platforms, including polaritonic materials and silicon photonics. This multidisciplinary research plan combines the fields of NZI media, metamaterials, quantum optics, electron-beam spectroscopy, thermal emission and silicon photonics.
Our objectives include the development of a novel technology of thermal emitters, which is key for heat and energy management applications, including renewable energies such as thermophotovoltaics and radiative cooling. We also aim to make an impact within the field of integrated photonics, a rapidly growing field with an increasingly dominant role in communication, sensing and LIDAR, computing, and quantum technologies, as well as in neural networks and artificial intelligence.
These unconventional effects have a high potential for technological innovation. However, the crucial challenge of transforming these basic phenomena into practical devices has not yet been addressed. In NZINATECH, we are addressing this challenge by pushing forward the basic theoretical research on NZI media to the stage of NZI nanophotonic technologies. To this end, we are carrying out an ambitious research plan that includes the experimental demonstration of NZI devices in different material platforms, including polaritonic materials and silicon photonics. This multidisciplinary research plan combines the fields of NZI media, metamaterials, quantum optics, electron-beam spectroscopy, thermal emission and silicon photonics.
Our objectives include the development of a novel technology of thermal emitters, which is key for heat and energy management applications, including renewable energies such as thermophotovoltaics and radiative cooling. We also aim to make an impact within the field of integrated photonics, a rapidly growing field with an increasingly dominant role in communication, sensing and LIDAR, computing, and quantum technologies, as well as in neural networks and artificial intelligence.
We have succeeded in developing and experimentally demonstrating a novel technology of NZI thermal emitters. These are lithography-free material-based emitters that do not require from complex nanofabrication processes, thus being compatible with large-area and low-cost applications. In addition, these are partially coherent emitters exhibit an unusually stable emission spectrum, robust against fabrication tolerances and the geometry of the device.
We have introduce another novel class of thermal emitters by opening the field on incandescent thermal emitters. Specifically, we have theoretically demonstrated the thermal emission from time-varying media is capable of surpassing blackbody radiation, induces nonlocal spatial and frequency correlations in thermal currents, and combines with quantum vacuum amplification effects at finite temperature. NZI thermal fluctuations are release as the frequency-momentum dual of a grating.
We have developed a nonperturbative theory of the coupling between small quantum systems and polaritonic modes in NZI materials. Among other effects, we have modelled optomagnonic coupling showing that strong coupling might be achievable at the NZI frequency. This result lies the basis for deterministic solid-state optical quantum interfaces for quantum memories and quantum state transfer.
We have starting developing integrated circuits harnessing the strong radiative losses of NZI materials. In addition, we have demonstrated that radiative losses can act as a resource for quantum networks with a smaller footprint and number of elements, as well as integrated optical amplifiers with an improved noise performance.
We have introduce another novel class of thermal emitters by opening the field on incandescent thermal emitters. Specifically, we have theoretically demonstrated the thermal emission from time-varying media is capable of surpassing blackbody radiation, induces nonlocal spatial and frequency correlations in thermal currents, and combines with quantum vacuum amplification effects at finite temperature. NZI thermal fluctuations are release as the frequency-momentum dual of a grating.
We have developed a nonperturbative theory of the coupling between small quantum systems and polaritonic modes in NZI materials. Among other effects, we have modelled optomagnonic coupling showing that strong coupling might be achievable at the NZI frequency. This result lies the basis for deterministic solid-state optical quantum interfaces for quantum memories and quantum state transfer.
We have starting developing integrated circuits harnessing the strong radiative losses of NZI materials. In addition, we have demonstrated that radiative losses can act as a resource for quantum networks with a smaller footprint and number of elements, as well as integrated optical amplifiers with an improved noise performance.
Our results already represent a significant progress with respect to the state-of-the-art, having introduced new nanophotonic technologies and novel theoretical formalisms. We expect to continue deepen into the technological development of NZI thermal emitters and integrated circuits. In addition, fundamental research on quantum optics of NZI media is expected to unveil new phenomena. Finally, our preliminary results on quantum and thermal noise management motivate us to further pursing applications for integrated amplifiers and quantum light sources.