Guided Matter-Wave Resonant Atom Interferometry for Gravitational-Wave Detectors

Atom interferometry could complement existing and future laser-interferometric gravitational-wave observatories: this presentation describes a new experimental technique, guided matter waves, to enhance resonant atom-interferometer performance. Building on an existing tabletop atom interferometer at Los Alamos National Laboratory, two Rubidium-87 clouds are interrogated for more than 40 ms, to yield acceleration measurements better than 8 micro-g. This experiment aims for 1-s interrogation times (already reaching 150 ms). Differential detection with lock-in amplification is expected to significantly reduce seismic coupling in the 100-mHz to 10-Hz band. Using guided matter waves, resonant atom interferometer designs could provide critical gravity-gradiometry measurements in compact sensors, without the need for large free-fall towers. This technology could support Cosmic Explorer and Einstein Telescope, potentially facilitating noise cancellation of limiting constraints on low-frequency sensitivity in the band between LISA and next-generation ground-based observatories. Guided matter-wave resonant atom interferometers might also offer direct gravitational-wave astrophysical measurements at specific, narrowband frequency ranges.