MRI: Track #1: Development of a System for Ultra-Low Temperature Spectroscopy of Quantum Emitters in Solids and 2-Dimensional Materials

Non-technical description: Quantum science and engineering research has made tremendous progress over the past two decades, moving from simple demonstrations of single quantum bits in various platforms to proof-of-concept demonstrations of quantum technologies, including quantum computers. These technologies are also of great national importance because of their promise to provide secure communication (quantum networks), better sensors for medicine and navigation (quantum sensors), and hardware much more powerful than today’s supercomputers for certain tasks (quantum computers and simulators). However, the discovery and development of suitable materials for such technologies has been one of the main bottlenecks in their scaling. We propose to develop an experimental setup for the study of new quantum materials. This will be a unique and interdisciplinary scientific tool that brings together multiple experimental techniques (cryogenics, optics, electronics) across science and engineering disciplines to achieve groundbreaking advances in quantum science and technology. This system will be used as a regional hub for quantum spectroscopy, and will provide training and mentorship for several generations of Ph.D. students, postdocs and undergraduates spanning multiple departments and institutions: Stanford Electrical Engineering, Materials Science, Applied Physics, and SLAC, as well San Jose State University and Santa Clara University. Technical description: We propose to develop a state-of-the-art experimental setup for the study of quantum materials including novel color center spin qubits and electro-optic materials, and the application of these material platforms toward scalable quantum technologies. The core of the instrument will be a state-of-the-art dilution refrigerator capable of achieving milli-kelvin base temperatures and with 3D vector magnetic fields of up to 1 Tesla. It will have a custom-made confocal microscope, coupled to tunable lasers and a high-resolution spectrometer, allowing for the study of quantum emitters over a broad range of frequencies. Advanced control electronics will enable sophisticated protocols, such as real-time feedforward and data-driven feedback, for exploring multi-qubit experiments with applications in quantum sensing, networking, and information processing. The unique proposed setup will ultimately enable the rapid discovery and comprehensive study of color center qubits and cryogenic electro-optic materials, which are essential building blocks for transducers and quantum interconnects, as well as the study of microwave and optical cavity QED systems. More broadly, this one-of-a-kind instrument will be set up as a shared facility, whose impact will extend beyond Stanford. The proximity to Silicon Valley will open the door for partnerships with industry, accelerating scaling, system integration, and real-world deployment. In addition, publications of the design of our instrument and detailed experimental protocols will accelerate the development of similar platforms in academic and national lab settings. 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.