We present a new model for creating a controlled spatial quantum memory which defined on space. This model is based on the mechanism in which two electromagnetic fields interact with a medium, and drive the same transition dipole. This interaction initiates Coherent Population Oscillations (CPO) of the quantum states to all orders in the frequency difference between the two electromagnetic fields.

The quantum system that we use consists of three states in which two of them,  and , are the ground and excited states respectively, that are electric dipole allowed, and the third state  acts as a shelving state that slowly decays to the ground state . The decay rates of the states lead to a long lifetime for the CPO which can be exploited for a new model of quantum memory. However, unlike known mechanisms based on EIT [1], photon and spin echo [2],[3] etc, we can not conserve the temporal profile of the weak field. This fact leads us to suggest a spatial memory that can be stored in the medium. In contrast to the famous mechanism of stored light based on EIT suggested by Lukin and Fleischhauer in 2000, which needs a thick medium for the process, our new model demand only a thin slab for memory creation [4].

We also present an expansion for this model which demonstrates the possibility of creating a multimode quantum memory based on CPO.

References

[1] M. Fleischhauer, and M. D. Lukin, Phys. Rev. Lett. 84, 5094 (2000).

[2] A. L. Alexander and J. J. Longdell and M. J. Sellars and N. B. Manson, Phys. Rev. Lett. 96, 043602 (2006).

[3] S. A. Moiseev and N. M. Arslanov, Phys. Rev. A. 78, 023803 (2008).

[4] I. Novikova, D. F. Phillips, and R. L. Wolsworth, Phys. Rev. Lett. 99, 173 (2008).