The group of Prof. Vuletic, at MIT, demonstrated that reversing the time in an atomic sensor can lead to a strongly enhanced sensitivity. With this time-reversal protocol, sensors can be operated with highly-entangled states which carry large statistical information close to the fundamental Heisenberg Limit.  Due to their fragility, these “superior” quantum states are extremely...

Optical lattice clocks (OLC) are widely recognized as the next golden standard for timekeeping. Over the past decades, researchers around the world have made the second the best characterized among all seven of International System of Units (SI units), reaching an unprecedented fractional stability at few parts-of-ten-Quintillion (1019). Despite the tremendous effort of improving technology...