Detecting gravitational waves with atomic sensors

The recent detections of gravitational waves (GW) by the LIGO and VIRGO Collaborations opened a new era in the fields of physics and astrophysics. The possibility to explore the Universe with a new type of messenger paves the way for the observations of a novel class of phenomena otherwise not detectable in the electromagnetic spectrum. To this end, new space-based and ground-based experiments are planned in the near future to extend the detectable frequency band and improve the sensitivity of the existing instruments. In this paper, we present the possibility of using atom interferometry for GW detection in the mHz to about 10 Hz frequency band. After a discussion about the possible GW sources to be studied, we will provide an intuitive description of the measurement principle, highlighting the differences between detectors based on two-photon and single-photon transitions. Important noise sources which are expected in such devices are briefly ex- plained. We finally present the perspective for the realisation of a future large-scale demonstrator.