Editorial on the GRG special issue on "Gravitational waves detection with atom interferometry"

This year 2011 marks the 20th anniversary of atom interferometry. It started with microfabricated mechanical beam splitters, namely double slits as used by Carnal and Mlynek [1] and gratings used by the group of Pritchard [2]. A few months later the first atom interferometers based on laser beams as beam splitters and mirrors have been built by Riehle et al. [3] and Kasevich and Chu [4]. After the first demonstration of their functioning these atom interferometers using laser beams as optical elements have been improved to become sensitive accelerometers and gyroscopes as has been first proposed by Bordé [5] as well as tools for various fundamental physics experiments (see, e.g., the reviews [6,7])....