Entanglement Swapping of Two Arbitrarily Degraded Entangled States
Abstract
We consider entanglement swapping, a key component of quantum network operations and entanglement distribution. Pure entangled states, which are the desired input to the swapping protocol, are typically mixed by environmental interactions causing a reduction in their degree of entanglement. Thus an understanding of entanglement swapping with partially mixed states is of importance. Here we present a general analytical solution for entanglement swapping of arbitrary two-qubit states. Our result provides a comprehensive method for analyzing entanglement swapping in quantum networks. First, we show that the concurrence of a partially mixed state is conserved when this state is swapped with a Bell state. Then, we find upper and lower bounds on the concurrence of the state resulting from entanglement swapping for various classes of input states. Finally, we determine a general relationship between the ranks of the initial states and the rank of the final state after swapping.
Keywords
Cite
@article{arxiv.1512.06093,
title = {Entanglement Swapping of Two Arbitrarily Degraded Entangled States},
author = {Brian T. Kirby and Siddhartha Santra and Vladimir S. Malinovsky and Michael Brodsky},
journal= {arXiv preprint arXiv:1512.06093},
year = {2016}
}