Determination of the newtonian gravitational constant using atom interferometry

We present a new measurement of the Newtonian gravitational constant G based on cold-atom interferometry. Freely falling samples of laser-cooled rubidium atoms are used in a gravity gradiometer to probe the field generated by nearby source masses. In addition to its potential sensitivity, this method is intriguing as gravity is explored by a quantum system. We report a value of G=6.667x10(-11) m(3) kg(-1) s(-2), estimating a statistical uncertainty of +/- 0.011x10(-11) m(3) kg(-1) s(-2) and a systematic uncertainty of +/- 0.003x10(-11) m(3) kg(-1) s(-2). The long-term stability of the instrument and the signal-to-noise ratio demonstrated here open interesting perspectives for pushing the measurement accuracy below the 100 ppm level.