# Measurement-device-independent quantification of irreducible high-dimensional entanglement

## TL;DR

This paper introduces a measurement-device-independent method to certify irreducible high-dimensional entanglement, ensuring genuine quantum correlations that cannot be simulated by lower-dimensional states, with experimental validation on a 3-dimensional system.

## Contribution

It defines irreducible entanglement and provides a protocol to detect it in a measurement-device-independent way, advancing quantum system characterization.

## Key findings

- Successfully certified 3-dimensional irreducible entanglement experimentally.
- Proved the detection method works in a measurement-device-independent manner.
- Established a new concept of irreducible entanglement for quantum systems.

## Abstract

The certification of entanglement dimensionality is of great importance in characterizing quantum systems. Recently, it is pointed out that quantum correlation of high-dimensional states can be simulated with a sequence of lower-dimensional states. Such problem may render existing characterization protocols unreliable---the observed entanglement may not be a truly high-dimensional one. Here, we introduce the notion of irreducible entanglement to capture its dimensionality that is indecomposable in terms of a sequence of lower-dimensional entangled systems. We prove this new feature can be detected in a measurement-device-independent manner with an entanglement witness protocol. To demonstrate the practicability of this technique, we experimentally apply it on a 3-dimensional bipartite state and the result certifies the existence of irreducible (at least) 3-dimensional entanglement.

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Source: https://tomesphere.com/paper/1901.00999