Experimental Entanglement Quantification for Unknown Quantum States in a Semi-Device-Independent Manner

TL;DR

This paper presents a semi-device-independent method to quantify entanglement in unknown quantum states using non-degenerate Bell inequalities, demonstrated experimentally on multi-level and multi-partite systems.

Contribution

It introduces a novel approach for entanglement quantification that requires minimal assumptions and is applicable to complex quantum systems, advancing quantum characterization techniques.

Findings

Successfully quantified entanglement of formation and distillation for qutrit-qutrit systems.

Measured the geometric entanglement of three-qubit systems.

Demonstrated applicability to multi-level and multi-partite quantum states.

Abstract

Using the concept of non-degenerate Bell inequality, we show that quantum entanglement, the critical resource for various quantum information processing tasks, can be quantified for any unknown quantum states in a semi-device-independent manner, where the quantification is based on the experimentally obtained probability distribution and beforehand knowledge on quantum dimension only. Specifically, as an application of our approach on multi-level systems, we experimentally quantify the entanglement of formation and the entanglement of distillation for qutrit-qutrit quantum systems. In addition, to demonstrate our approach for multi-partite systems, we further quantify the geometry measure of entanglement of three-qubit quantum systems. Our results supply a general way to reliably quantify entanglement in multi-level and multi-partite systems, thus paving the way to characterize many-body quantum systems by quantifying involved entanglement.