Testing quantum entanglement with local measurement

TL;DR

This paper introduces a local measurement-based condition to detect quantum entanglement efficiently in pure states, applicable to both discrete and continuous systems, and robust against noise, enabling loophole-free tests.

Contribution

It presents a new local measurement criterion for entanglement detection that is noise-resistant and applicable across different quantum systems, facilitating more reliable experimental verification.

Findings

Efficient detection of pure entangled states in discrete and continuous systems.

Condition is robust against decoherence, noise, and detection loss.

Enables loophole-free tests of quantum entanglement.

Abstract

We propose to detect quantum entanglement by a condition of local measurments. We find that this condition can detect efficiently the pure entangled states for both discrete and continuous variable systems. It does not depend on interference of decoherence from noise and detection loss in some systems, which allows a loophole-free test in real experiments. In particular, it is a necessary condition for the violation of some generalized Bell inequalities.