EAGER: Photo-Activated Currents and Magnetization in Au-Nanorings (PACMAN)

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The main goal of this program is to prove the feasibility of photo-activating currents and photo-inducing magnetization in noble metal-nanorings using polarization controlled laser radiation.The specific objectives of this investigation are: i) To couple the laser system with a microscale Hall-effect magnetometer, ii) To find, theoretically, optimum experimental configurations of two-dimensional Au-nanorings arrays to be tested, iii) To fabricate the first series of samples on quartz and GaAs wafers based on the theoretical predictions, iv) To demonstrate the generation of rotating polaritons in Au-Nanorings through the optical characterization of samples supported on quartz, v) To measure photo-induced magnetization in Au-nanorings supported on GaAs-wafers with the integrated microscale Hall-Effect magnetometer under perpendicular radiation geometry, using left and right circularly polarized light.Intellectual Merit: This EAGER is a fundamental, high-risk, high-reward transformative research project that crosses traditional boundaries between chemistry, physics, optics, material sciences, engineering and nanotechnology.? This project is transformative in that the current understanding of polariton propagation in conductive nanostructures will be enriched by a valuable fundamental study of the generation of controlled photo-induced transient rotating polaritons in closed metal nanorings using circularly polarized radiation with specific handedness. This exceptionally innovative research project offers the potential to pave the road of a new generation of nanodevices that could be used as photo-activated binary switchable nanomagnets, photo-activated nano-accelerators, photo-activated magnetic nano-transmitters, and meta-materials for negative refractive index, among others.? The high-reward aspect of this EAGER resides in the deep understanding of an intriguing but fascinating effect that could revolutionize the field of nanotechnology through the development and design of novel nanodevices for computing and communication, nanoantennas and sensors.? The high-risk facet of this study resides mainly on the intrinsic uncertainty involved in a high-impact, cutting edge research on an untested idea and, on the multidisciplinary experimental technical challenges that it will present. The latter include to couple a laser system with a microscale Hall-Effect magnetometer, to fabricate nanostructures with reduced defects and increase the density of Au-nanorings on the substrates avoiding surface Plasmon resonance coupling between neighbor nanorings, to detect the anticipated small photo-induced currents and magnetization in Au-nanorings and, to gain control on the sign of the magnetization using different handedness of circularly polarized radiation. Broader Impact: This project includes the interdisciplinary training of two graduate students of two different disciplines (chemistry and physics) in a field that combines chemistry, physics, optics, material sciences, engineering and nanotechnology. The strong collaboration between USA and Taiwan, an Asian developing nation, will contribute to the preparation of the new generation of PhDs by providing them with global awareness. Results will be diseminated through publications in peer-reviewed journals and conference presentations.