This project, a collaborative project between the University of Wisconsin-Madison and scientists and engineers at Northrop-Grumman Corporation, will further develop new concepts in ultrahigh sensitivity nuclear magnetic resonance (NMR). The idea is make precise measurements of the motions of nuclear spins due to magnetic fields, inertial rotations, or hypothetical new spin-dependent forces of nature. It is noteworthy that such measurements have both practical impact (miniature gyroscopes for navigation, for example) and can be used to test new ideas related to dark matter in the universe. This is an example of a potentially practical device that uses basic features of quantum mechanics to make measurements of macroscopic properties of motion.
The underlying principles of the project rely on the application of NMR bias magnetic fields in the form of a sequence of short pulses of well-defined areas that act, in concert with time-dependent optical pumping, to allow alkali atoms and noble-gas nuclei to precess at the same frequency despite having magnetic moments that are different by 3 orders of magnitude. Both species are polarized and precess entirely transverse to the bias field. This greatly suppresses the dominant systematic errors that are known to affect traditional designs of such instruments, but retains the benefits of ultra-sensitive readout of the NMR precession using the embedded alkali magnetometer. Estimates of technical noise indicate the system has a potential frequency noise level of better than 10 nHz/sqrt(Hz), with fundamental limits that are much better. Previous work has demonstrated the basic properties of this system; this project will study systematic errors and improve the statistical uncertainties. The system will be tested as a precision NMR gyro, of great interest to the industrial partners, and will be used to set new mass and sensitivity limits in searches for axion-like particles.
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.
