Date Jan 23, 2012, 2:00 pm – 3:30 pm Location Jadwin A06 Share on X Share on Facebook Share on LinkedIn Details Event Description Over a decade ago, the stability of atomic clocks reached the standard quantum limit, set by the projection noise inherent in measurements on an ensemble of uncorrelated particles. In a proof of-principle experiment, we have now demonstrated a clock that surpasses this limit by operating with atoms in a particular type of entangled state called a "squeezed spin state." I will describe our method of preparing squeezed spin states, which harnesses the collective interaction of an atomic ensemble with the light field in an optical cavity. I will further present data characterizing the squeezed clock, including the first measurement of an Allan deviation beyond the standard quantum limit.