New aspects of entanglement dynamics are presented. Firstly, it is shown that two systems can be entangled via exchange of an unentangled messenger particle in a mixed state. The same result holds for two systems interacting indirectly via a third. However, for the special case of pure states, a quantitative relation can be derived between the entanglement rate of the two systems and the entanglement of the mediating system. The latter acts as a bottleneck to entanglement flow. For general many-body systems, including systems in mixed states, a set of entanglement rate equations is derived, analogous to the rate equations for a chemical reaction. These are used to prove a lower-bound on the time required to entangle distant particles. Finally, the correlation dynamics of a spin model is analysed using a fermionic gaussian state formalism, and it is shown that the correlations can be precisely controlled using only external parameters.
«New aspects of entanglement dynamics are presented. Firstly, it is shown that two systems can be entangled via exchange of an unentangled messenger particle in a mixed state. The same result holds for two systems interacting indirectly via a third. However, for the special case of pure states, a quantitative relation can be derived between the entanglement rate of the two systems and the entanglement of the mediating system. The latter acts as a bottleneck to entanglement flow. For general many-...
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