: Quantum Gravity Gradiometer Pathfinder (QGG Pf): Technology development for atom interferometric gravity recovery from low Earth orbit

The technology of utilizing the interference of laser cooled atoms for ultra-sensitive inertial and gravity sensors has been maturing for the past three decades. In particular, gravity gradiometery based on two cold atom interferometers (AIs) separated by a fixed baseline and a common AI laser has been demonstrated terrestrially with sensitivities less than 100 Eotvos/√Hz. In the microgravity environment of low-Earth orbit, a sensor in this configuration could achieve an order of magnitude improvement over the current GRACE dual satellite mission in a single satellite. In this talk, we will present the instrument architecture and physics protocols for NASA’s Quantum Gravity Gradiometer (QGG) Pathfinder instrument. The proposed instrument is a single-axis QGG derived from a single ⁸⁷Rb Bose-Einstein Condensate delta-kick collimated to an effective temperature of 100 pK. This single cloud is transported to the AI region, split into separate clouds, and precisely positioned into the gradiometer configuration via optical lattices. A Mach-Zehnder AI sequence is performed simultaneously at each cloud via multi-photon Bragg diffraction. The phase of each AI is read out via imaging the spatial fringes in each interfered ensemble. The talk will include a discussion of technical trades, expected error sources, and subsystem requirements.