A New Method for Compact, High-Performance Atom Interferometric Sensors
Abstract
Light-pulse atom interferometry--in which laser pulses split, recombine, and interfere quantum mechanical atomic matter waves--is a valuable tool for a broad set of practical measurements and fundamental physics tests. Recent advances have enabled atom interferometers that enclose a large spacetime area between their two arms (up to tens of centimeters spatial separation between the arms, for a duration on the scale of one second), dramatically improving interferometer sensitivity to inertial and gravitational forces. Thesensitivity of these interferometers was in large part enabled by using a 10-meter-tall atomic fountain, which allowed for multiple seconds of free-fall. Such a large apparatus cannot be used outside the laboratory for a practical sensor, and many other experiments of fundamental interest would also benefit from a more compact apparatus. The main research problem addressed by this proposal is to develop techniques that allow atom interferometers to achieve sensitivities similar to--or even larger than--those demonstrated in 10-meter-scale apparatus while maintaining a much smaller sensor size (50 cm or smaller sensor height). The technical approach centers on utilizing atom interferometers that employ optical lattices to rapidly split the interferometer arms and to levitate the atoms against gravity, enabled by a novel method for compensating spurious laser-intensity-dependent phase shifts induced bythe lattice-atom interaction. If left uncompensated, these phase shifts would rapidly lead to decoherence, severely limiting sensor performance. The levitation allows for long interferometer durations without the need for a ten-meter-tall atomic fountain, and the large momentum beam splitting enhances sensitivity. The beam splitting and levitation require the atoms to receive large momentum transfer (LMT) kicks, which optical lattices can deliver with an atom loss rate100 times less than other methods. Moreover, the lattice-based atom interferometers will be implemented with Sr-88 atoms, which have ideal characteristics for quantum sensing and precision measurement (very low residual magnetic field sensitivity and atom-atom interactionstrength).
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 25, 2019
- Source ID
- N000141912181
Entities
People
- Timothy Kovachy
Organizations
- Northwestern University
- Office of Naval Research
- United States Navy