Analytic results on long-distance entanglement mediated by gapped spin chains
Aires Ferreira, J. M. B. Lopes dos Santos · Physical Review A · 2008
Recent numerical results showed that spin chains are able to produce long-distance entanglement (LDE). We develop a formalism that allows the computation of LDE for weakly interacting probes with gapped many-body systems. At zero temperature, a dc response function determines the ability of the physical system to generate genuine quantum correlations between the probes. We show that the biquadratic Heisenberg spin-1 chain is able to produce LDE in the thermodynamic limit and that the finite antiferromagnetic Heisenberg chain maximally entangles two spin-$1/2$ probes very far apart. These results support the current perspective of using quantum spin chains as entanglers or quantum channels in quantum information devices.