Gaussian localizable entanglement

TL;DR

This paper studies how to concentrate entanglement between two modes in multimode Gaussian states using local measurements, showing Gaussian measurements are optimal for pure and symmetric states, but non-Gaussian measurements can do better.

Contribution

It demonstrates the effectiveness of local Gaussian measurements for entanglement localization and highlights the advantage of non-Gaussian measurements for enhanced entanglement.

Findings

Homodyne detection maximizes entanglement localization in pure and symmetric states.

Non-Gaussian measurements can localize more entanglement than Gaussian ones.

Maximum entanglement achieved with projections onto infinitely squeezed states.

Abstract

We investigate localization of entanglement of multimode Gaussian states into a pair of modes by local Gaussian measurements on the remaining modes and classical communication. We find that for pure states and for mixed symmetric states maximum entanglement between two modes can be localized by local homodyne detections, i.e. projections onto infinitely squeezed states. We also show that non-Gaussian measurements allow to localize more entanglement than Gaussian ones.