Perfect lens with hybrid structure of dielectric and atomic gas

A perfect lens constructed by dielectric and atomic gas slab system is investigated. By utilizing quantum coherence, the atomic gas shows simultaneous negative permittivity and permeability. Meanwhile, the loss can be neglected. The light emitted by one point source in the dielectric can be focused to another point in the other dielectric, which induces strong and long range dipole–dipole interaction. Consequently, large entanglement between two qubits can be generated. Meanwhile, due to the low loss of our model, the entanglement can be preserved for a long time. (paper)