Collaborative Research: FET: Foundations of Computing with Nanobridge Josephson Junctions

Today’s computers are beginning to fall short of what we need for the next generation of science and technology. From designing new medicines and materials to securing information and capturing images of distant galaxies, many important problems require systems that are faster, use less energy, and can make more precise measurements than what we have today. Current technologies struggle to do all of these things at once, which is why new kinds of devices are needed. The challenge is that building new technologies usually takes a very long time—often decades—because progress happens in incremental steps. This project aims to speed things up by designing devices that are simpler to build, smaller in size, and still very powerful. The key focus is on electronics that operate at extremely cold temperatures, known as cryogenic electronics. These systems behave differently from everyday electronics and can offer major advantages in speed and energy use, opening the door to entirely new capabilities rather than just small improvements. In addition, this project will create training materials to help people from different technical backgrounds to learn about this emerging field. It will also be a forum for discussion among researchers with diverse technical backgrounds. Ultimately, the goal is to create a clear path for turning new ideas for devices into real-world systems that can benefit society. This project seeks to establish a scalable computing framework based on nano-scale superconducting switches (nanobridge, or Dayem bridge, Josephson junctions) to overcome the density and fabrication limitations of conventional superconducting electronics, with the goal of achieving significantly higher integration density through a simplified fabrication process. The project combines device design, circuit development, and software tool support in a unified approach: it will first investigate how nanoscale geometry and materials influence device behavior through simulation and experimental characterization and then use these insights to design and optimize robust logic cells and circuits using a technology-optimized signal encoding. These designs will be fabricated and tested to validate performance, while corresponding models and standardized libraries will be integrated into existing electronic design automation workflows to enable larger system design. Throughout the project, feedback between fabrication and design will be used to improve performance and reliability, alongside the development of methods to manage variability and detect or correct errors. This end-to-end approach—from materials and devices to circuits and design tools—aims to (1) demonstrate that simpler superconducting devices can deliver energy-efficient, scalable computing for quantum and cryogenic sensing systems, and (2) establish a generalizable, cross-layer design methodology that accelerates innovation beyond current fabrication limits. 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.