CAREER: Electrically Reconfigurable Chiroptical Heterostructures based on Twisted Aligned 1D Chiral Quantum Materials and Phase Change Materials

Non-technical Description The interaction of chiral materials and devices with circularly polarized light creates new opportunities for applications in sensing, imaging, computing, and quantum photonic technologies. However, current chiroptical platforms face challenges, including limited understanding and electrical control of key chiroptical responses, a narrow range of material choices, manufacturing processes that are challenging to scale, and the lack of fast, accurate simulation and design tools that can incorporate chiral materials. To address these challenges, this project develops a scalable and electrically reconfigurable chiroptical platform based on one-dimensional chiral quantum materials and reconfigurable photonic materials, together with a high-performance solver for fast simulation and inverse design. Carbon nanotubes (CNTs) and nonvolatile phase change materials (PCMs) serve as example material systems. The resulting heterostructure and solver can be extended to a broad range of materials and device structures to explore fundamental chirality-induced phenomena, enable functional devices, and serve a broad community. This project also integrates research with education through community building, multilevel student training, curriculum development, and outreach, helping cultivate future engineers and scientists in semiconductor optics and optoelectronics. Technical Description This project aims to address current limitations in the practical deployment of the proposed chiroptical heterostructure and solver, including weak chiroptical responses, binary and one-way electrical reconfigurability, and the solver’s inability to handle chiral materials, complex structures, and experimental variations. Specifically, this project combines molecular and structure-induced chiralities from strong excitons in twisted aligned semiconducting CNT enantiomers, increases the number of stacking layers with low-loss PCMs, and creates planar Moiré cavities to enhance chiroptical responses. In addition, the small-sized cavities controlled by aligned metallic CNT films enable reversible and multilevel reconfigurability. Further, this project develops a high-performance chiral rigorous-coupled-wave-analysis solver powered by graphics-processing-unit-accelerated simulation and differentiable inverse design, supporting general bi-anisotropic materials, two-dimensional periodic patterns of arbitrary shapes, and robust design in experiments. 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. NSF Award ID: 2541942 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Weilu Gao | Institution: University of Utah, SALT LAKE CITY, UT | Award Amount: $521,455 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2541942 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2541942.html