Using Atomic Clocks to Detect Gravitational Waves

TL;DR

This paper proposes using a network of highly precise atomic clocks distributed around Earth's orbit to detect millihertz gravitational waves from distant supermassive black hole binaries, offering an alternative to interferometric methods.

Contribution

It introduces a novel method for gravitational wave detection using atomic clock arrays, leveraging recent advances in clock precision and orbital distribution.

Findings

Atomic clocks can detect mHz gravitational waves via time dilation effects.

Distributed clocks around Earth's orbit improve sensitivity to gravitational waves.

This method offers an alternative to traditional interferometric GW detection techniques.

Abstract

Atomic clocks have recently reached a fractional timing precision of $<10^{-18}$. We point out that an array of atomic clocks, distributed along the Earth's orbit around the Sun, will have the sensitivity needed to detect the time dilation effect of mHz gravitational waves (GWs), such as those emitted by supermassive black hole binaries at cosmological distances. Simultaneous measurement of clock-rates at different phases of a passing GW provides an attractive alternative to the interferometric detection of temporal variations in distance between test masses separated by less than a GW wavelength, currently envisioned for the eLISA mission.