  A double rephasing photon echo is analyzed for inversion-free photon
echo-based quantum memories using controlled Rabi flopping, where the Rabi
flopping is used for phase control of atom coherence. Unlike the
rephasing-caused pi-phase shift in a single rephasing scheme, the control Rabi
flopping between the excited state and an auxiliary third state induces
coherence inversion. Thus, the absorptive photon echo in a double rephasing
scheme can be manipulated to be emissive via the controlled Rabi flopping. Here
we present a quantum coherence control of atom phases in a double rephasing
photon echo scheme for emissive photon echoes for quantum memory applications.
