## PT Symmetry via Electromagnetically Induced Transparency    [PDF]

Huijun Li, Jianpeng Dou, Jinjin Yang, Guoxiang Huang
We propose a scheme to realize parity-time ($\mathcal{PT}$) symmetry via electromagnetically induced transparency (EIT). The system we consider is an ensemble of cold four-level atoms with an EIT core. We show that the cross-phase modulation contributed by an assisted field, the optical lattice potential provided by a far-detuned laser field, and the optical gain resulted from an incoherent pumping can be used to construct a $\mathcal{PT}$-symmetric complex optical potential for probe field propagation in a controllable way. Comparing with previous study, the present scheme uses only a single atomic species and hence is easy for the physical realization of $\mathcal{PT}$-symmetric Hamiltonian via atomic coherence.
View original: http://arxiv.org/abs/1307.2695