Analytic results on long distance entanglement mediated by gapped spin chains

TL;DR

This paper provides an analytical framework for understanding long-distance entanglement mediated by gapped spin chains, demonstrating their potential as quantum channels for entanglement distribution.

Contribution

It introduces a formalism to compute long-distance entanglement in gapped spin chains and shows their effectiveness in generating quantum correlations between distant probes.

Findings

Biquadratic Heisenberg spin-1 chain can produce LDE in the thermodynamic limit.

Finite antiferromagnetic Heisenberg chain maximally entangles distant spin-1/2 probes.

Analytical description aligns with numerical studies and supports quantum information applications.

Abstract

We give an analytical description of long distance entanglement (LDE) mediated by one-dimensional quantum spin chains recently found in numerical studies. 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 thermodynamical 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.