CAREER: Probing and Understanding Nonreciprocal and Topological Radiative Heat Transport in Many-Body Magnetized Systems

Radiative heat transfer is everywhere, ranging from sunlight and incandescent lighting to thermal imaging. Controlling radiative heat transfer is critical for creating efficient solar energy harvesting, cooling, lighting, and imaging. However, experiments of radiative heat transfer have been limited to non-magnetic materials. Systems containing magnetized objects are expected to support many new effects of radiative heat transfer, with potential applications such as efficient heat exchange and energy conversion. To create these revolutionary technologies, it is essential to experimentally study and understand radiative heat transfer among at least three magnetized objects and to explore the use for improving heat exchange and energy conversion. Here, the Principal Investigator will develop a novel technique that will enable the study of radiative heat transfer among magnetized objects. The knowledge obtained in the proposed work points to applications such as thermal switches, energy harvesting, cooling, and magnetic sensing. The insights obtained in this work will make it possible to improve heat exchange for energy conversion, such as for harvesting sunlight, waste heat, and cooling. Educational and outreach activities include organizing "Thermal Emission for Energy with Nanoscience" workshops to train secondary precollege teachers for low-cost, hands-on activities that can be readily integrated into their classes. Micro-credentialing activities will be organized to introduce advances in radiative heat transfer to undergraduates. These multi-level educational and outreach activities increase involvement in science and engineering, promote STEM education and educator development, and motivate students to address critical global challenges. Radiative heat transport is essential for solar energy harvesting, radiative cooling, lighting, and imaging. However, experiments of radiative heat transport have been fundamentally limited by the time reversal symmetry. By breaking the time reversal symmetry, many-body magnetized systems (MBMS) consisting of at least three bodies made of magnetized semiconductors or magnetic quantum materials are expected to support vastly new phenomena of radiative heat transfer, with potentials for various technological applications. To create these revolutionary technologies, it is essential to probe and understand: 1) nonreciprocal radiative heat transport, 2) topological radiative heat transport, and 3) their use for improving heat exchange and energy conversion. A novel technique that will enable the study of radiative heat transport in MBMS will be developed in this project. Using this technique, for the first time, experiments will be conducted to probe nonreciprocal and topological radiative heat transport. Further, the use of MBMS for improving heat exchange and energy conversion will be explored. This program points to opportunities in the new research fields of nonreciprocal and topological thermal transport. The knowledge obtained in the proposed work points to applications such as dynamical control of heat flux, energy harvesting, refrigeration, and magnetic detection. The insights obtained in this work will make it possible to improve heat exchange for energy conversion, such as for harvesting sunlight, waste heat, and cooling. A multi-level educational and outreach plan includes: (1) organizing "Thermal Emission for Energy with Nanoscience" (TEEN) workshops to train secondary precollege teachers for low-cost, hands-on activities that can be easily integrated into their classes, in regions with a high percentage of prospective first-generation college students; (2) organizing micro-credentialing activities to introduce advances in nanoscale thermal radiation to undergraduates; (3) creating a new graduate course on nanoscale thermal radiation, which will be made available to the national and international community through the NSF-supported "nanohub", an online repository of courses. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.