QuSeC-TAQS: Development of Quantum Sensors with Helium-4 using 2D Materials

This project combines two exotic materials, superfluid helium and nanoporous two-dimensional polymers, to develop a sensor device that takes advantage of the strange macroscopic quantum behavior of liquid helium at temperatures near absolute zero. A nanoporous membrane will provide a weak link between two reservoirs of superfluid helium, and enable a quantum coupling known as a Josephson junction. The resulting transport of superfluid between reservoirs is predicted to have unusual properties described by quantum mechanics. Quantum sensors based on this architecture will allow measurement of phenomena that is undetectable to conventional sensors, from minute fluctuations in the Earth’s rotation to the fingerprints of dark matter. The technical applications for of this quantum sensor are widespread. They are found in disciplines spanning geodesy (GPS and geological exploration), gravitation and general relativity (dark matter and cosmology), metrology (quantum standards for physical quantities), and quantum information (quantum computing). Exploring Josephson junctions for superfluid helium can enable new capabilities that are useful in several scientific disciplines. The key hypothesis is that nanoporous two-dimensional crystal polymer membranes will enable superfluid helium-4 Josephson junction structures. This project is designed to demonstrate superfluid Josephson junctions and explore how to control and measure the quantum transport of superfluid through the restricted geometry of a nanoporous membrane. The fundamental noise properties of the junctions will be studied in order to understand the ultimate performance of matter wave interference devices, gyroscopes, quantum limited amplifiers, quantum standards, and qubit structures based on this effect. As part of these experiments, this project will examine fundamental issues in condensed matter physics, quantum materials, materials science, and quantum engineering. This project will lay a foundation for new quantum devices such as superfluid SQUIDs, acoustic amplifiers, quantum standards, and qubits. 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.