First step towards a qubit based on spin triplet superconductors

Non-technical Abstract: This project explores a promising pathway toward fault-tolerant quantum computing by studying spin-triplet superconductors. These materials may host exotic quantum states that could serve as the foundation for robust quantum bits. The research focuses on fabricating and characterizing high-quality Josephson junctions to detect and control these states, addressing key experimental challenges that have limited progress in the field. In addition to advancing quantum technologies, the project includes a strong educational component. Graduate students will gain hands-on training in quantum materials research, while younger students will be introduced to quantum physics through illustrated books. Public interviews with leading physicists will further promote understanding of advanced science among broader audiences. Together, the research and outreach efforts aim to expand both the frontiers of quantum science and access to it. Technical Abstract: Spin-triplet superconductors offer a unique platform for realizing topological quantum states, including Majorana modes and intrinsic pi-junctions, which are essential building blocks for fault-tolerant quantum computing. However, experimental progress in this field has been severely limited by the technical challenges in fabricating high-quality Josephson junctions and characterizing their quantum properties. This project aims to overcome these barriers through the systematic fabrication and investigation of Josephson junctions based on UTe2 and other leading spin-triplet superconductor candidates. The project will establish a robust methodology for creating high-performance junctions, enabling precise measurements of the current-phase relation and direct detection of topological excitations. The research team will implement a combination of advanced fabrication techniques, corner-junction interferometry, and phase-sensitive transport measurements. The integrated experimental framework will also be extended to other spin-triplet superconductors, laying the groundwork for a broader class of topological quantum devices. Specific goals include: (1) Develop high-quality Josephson junctions based on spin-triplet superconductors; (2) Uncover the pi-junction behavior via phase-sensitive measurements; (3) Detect and control Majorana modes to enable topological quantum device applications. 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.