Efficient generation of hyperentangled photon pairs with controllable waveforms from cold atoms

We propose a scheme to efficiently generate time-frequency and polarization-entangled photon pairs with cold atomic ensembles via spontaneous four-wave mixing through combining the photon pairs from two symmetrical spatial modes by polarization beam splitters. With a two-dimensional magneto-optical trap, polarization-entangled photon pairs with controllable temporal length (>100 ns) can be generated at the rate of about 10(5) per second after taking into account all losses. Therefore, it is a feasible photon source for scalable linear optical quantum computation and long-distance quantum communication. (c) 2013 Optical Society of America