Demonstration of a multipulse interferometer for quantum kicked-rotor studies

We implemented a multipulse interferometer scheme that allows us to study a quantum kicked rotor by observing dephasing of momentum coherence. Our study shows that momentum coherence can be nearly perfectly preserved under conditions where the mean energy as a function of the kick number is known to increase without bound. The accompanying width narrowing of these coherences may provide a new method for accurate measurement of the recoil frequency.