Weak Values and Continuous-Variable Entanglement Concentration

TL;DR

This paper introduces a general weak measurement model enabling Gaussian-preserving entanglement concentration of two-mode squeezed vacuum states, unifying previous protocols and demonstrating its versatility through new examples.

Contribution

It presents a unified weak measurement framework for entanglement concentration, revealing constraints on ancilla states and measurement strategies, and includes novel protocol examples.

Findings

The model encompasses existing protocols as special cases.

It preserves Gaussian states during entanglement concentration.

New protocol examples demonstrate the model's utility.

Abstract

We demonstrate a general weak measurement model which allows Gaussian preserving entanglement concentration of the two mode squeezed vacuum. The power of this simple and elegant protocol is through the constraints it places on possible ancilla states and measurement strategies that will allow entanglement concentration. In particular, it is shown how previously discovered protocols of this kind emerge as special examples of the general model described here. Finally, as evidence of its utility, we use it to provide another novel example of such a protocol.