Rotation Sensing with an Atom Interferometer

We have measured the phase shift induced by rotation of an atom interferometer at rates of -2 to $+2$ earth rates and obtained $1%$ agreement with the predicted Sagnac phase shift for atomic matter waves. The rotational rms noise of our interferometer was $42$ milliearth rates for $1$ sec of integration time, within $9%$ of shot noise. The high sensitivity and agreement of predicted and measured behavior suggest useful future scientific applications of atom interferometers as inertial sensors.