4,601 research outputs found
Entanglement concentration for unknown atomic entangled states via entanglement swapping
An entanglement concentration scheme for unknown atomic entanglement states
is proposed via entanglement swapping in cavity QED. Because the interaction
used here is a large-detuned one between two driven atoms and a quantized
cavity mode, the effects of the cavity decay and thermal field have been
eliminated. These advantages can warrant the experimental feasibility of the
current scheme.Comment: 4 page
Quantum state transfer through a spin chain in a multi-excitation subspace
We investigate the quality of quantum state transfer through a uniformly
coupled antiferromagnetic spin chain in a multi-excitation subspace. The
fidelity of state transfer using multi-excitation channels is found to compare
well with communication protocols based on the ground state of a spin chain
with ferromagnetic interactions. Our numerical results support the conjecture
that the fidelity of state transfer through a multi-excitation subspace only
depends on the number of initial excitations present in the chain and is
independent of the excitation ordering. Based on these results, we describe a
communication scheme which requires little effort for preparation.Comment: 5 pages, 4 figure
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