Long-range interactions and entanglement of slow single-photon pulses
arXiv:quant-ph/0503071 · doi:10.1103/PhysRevA.72.043803
Abstract
We show that very large nonlocal nonlinear interactions between pairs of colliding slow-light pulses can be realized in atomic vapors in the regime of electromagnetically induced transparency. These nonlinearities are mediated by strong, long-range dipole--dipole interactions between Rydberg states of the multi-level atoms in a ladder configuration. In contrast to previously studied schemes, this mechanism can yield a homogeneous conditional phase shift of pi even for weakly focused single-photon pulses, thereby allowing a deterministic realization of the photonic phase gate.
4 pages, 2 figures