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.

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.