Gravitational wave detection with optical lattice atomic clocks

TL;DR

This paper proposes a space-based gravitational wave detector using two satellites with optical lattice atomic clocks, capable of detecting GWs in the 3 mHz to 10 Hz range, bridging the gap between existing detectors.

Contribution

It introduces a novel two-satellite GW detection scheme utilizing atomic clocks, offering a complementary and sensitive method for detecting low-frequency gravitational waves.

Findings

Sensitive to Doppler shifts caused by GWs

Detects continuous, narrowband sources like binary inspirals

Operates in the 3 mHz - 10 Hz frequency range

Abstract

We propose a space-based gravitational wave detector consisting of two spatially separated, drag-free satellites sharing ultra-stable optical laser light over a single baseline. Each satellite contains an optical lattice atomic clock, which serves as a sensitive, narrowband detector of the local frequency of the shared laser light. A synchronized two-clock comparison between the satellites will be sensitive to the effective Doppler shifts induced by incident gravitational waves (GWs) at a level competitive with other proposed space-based GW detectors, while providing complementary features. The detected signal is a differential frequency shift of the shared laser light due to the relative velocity of the satellites, and the detection window can be tuned through the control sequence applied to the atoms' internal states. This scheme enables the detection of GWs from continuous, spectrally narrow sources, such as compact binary inspirals, with frequencies ranging from ~3 mHz - 10 Hz without loss of sensitivity, thereby bridging the detection gap between space-based and terrestrial optical interferometric GW detectors. Our proposed GW detector employs just two satellites, is compatible with integration with an optical interferometric detector, and requires only realistic improvements to existing ground-based clock and laser technologies.