18,139 research outputs found
Generation of pure, ionic entangled states via linear optics
In this paper, we propose a novel scheme to generate two-ion maximally
entangled states from either pure product states or mixed states using linear
optics. Our new scheme is mainly based on the ionic interference. Because the
proposed scheme can generate pure maximally entangled states from mixed states,
we denote it as purification-like generation scheme. The scheme does not need a
Bell state analyzer as the existing entanglement generation schemes do, it also
avoids the difficulty of synchronizing the arrival time of the two scattered
photons faced by the existing schemes, thus the proposed new entanglement
generation scheme can be implemented more easily in practice.Comment: 6 pages, 4 figure
A note on directed 4-cycles in digraphs
Using some combinatorial techniques, in this note, it is proved that if
, then any digraph on vertices with minimum outdegree
at least contains a directed cycle of length at most 4
- …