Quantum memory based on controllable transition dipole moment

To build quantum memory for light with atomic ensembles one need to map single photons into atomic excitations and freeze them until releasing them back to photons on demand. Here we present an idea for realizing this storage-recall procedure by directly turning transition dipole moment on and off in a two-level system. An analytical treatment of the problem is performed and the physical requirements on the proposed scheme are discussed. Employing a magneto-dependent transition dipole moment in Tm3+: YAG crystal, we show a good instructive quantum memory using this simple idea.