Rabi oscillations revival induced by time reversal: a test of mesoscopic quantum coherence

Using a technique reminiscent of the spin-echo, the paper reports on the demonstration of the coherent superposition of the two dephased fields. The atom is first interacted with the field. Collapse of the Rabi oscillations is then observed. The phase distribution is measured to check that the field has been split into two components. A /spl pi/-pulse is applied that swaps the two atomic states correlated to the phase components. This amounts to a time-reversal operation. The field components then reverse their evolution in the phase plane, until they merge back together. An induced Rabi revival is observed that proves the coherence of the whole process.