Entanglement in general two-mode continuous-variable states: local approach and mapping to a two-qubit system
Abstract
We present a new approach to the analysis of entanglement in smooth bipartite continuous-variable states. One or both parties perform projective filterings via preliminary measurements to determine whether the system is located in some region of space; we study the entanglement remaining after filtering. For small regions, a two-mode system can be approximated by a pair of qubits and its entanglement fully characterized, even for mixed states. Our approach may be extended to any smooth bipartite pure state or two-mode mixed state, leading to natural definitions of concurrence and negativity densities. For Gaussian states both these quantities are constant throughout configuration space.
Cite
@article{arxiv.quant-ph/0608121,
title = {Entanglement in general two-mode continuous-variable states: local approach and mapping to a two-qubit system},
author = {H. -C. Lin and A. J. Fisher},
journal= {arXiv preprint arXiv:quant-ph/0608121},
year = {2009}
}
Comments
4 pages, RevTeX 4, one figure. Further modifications in response to journal referees, correction to expression for negativity