New Method for Gravitational Wave Detection with Atomic Sensors

TLDR

Laser frequency noise dominates gravitational‑wave detection with long‑baseline interferometry, and mitigating it requires simultaneous strain measurements on multiple baselines, implying additional satellites or interferometer arms. The authors propose a new detection strategy using optical atomic clocks and atom interferometry that operates at long baselines and is immune to laser frequency noise. The method suppresses laser frequency noise by deriving the signal solely from the light propagation time between two atomic ensembles. The sensor enables sensitive gravitational‑wave detection with a single baseline and offers practical applications such as ultrasensitive gravimeters and gravity gradiometers.

Abstract

Laser frequency noise is a dominant noise background for the detection of gravitational waves using long-baseline optical interferometry. Amelioration of this noise requires near simultaneous strain measurements on more than one interferometer baseline, necessitating, for example, more than two satellites for a space-based detector or two interferometer arms for a ground-based detector. We describe a new detection strategy based on recent advances in optical atomic clocks and atom interferometry which can operate at long baselines and which is immune to laser frequency noise. Laser frequency noise is suppressed because the signal arises strictly from the light propagation time between two ensembles of atoms. This new class of sensor allows sensitive gravitational wave detection with only a single baseline. This approach also has practical applications in, for example, the development of ultrasensitive gravimeters and gravity gradiometers.