Genuine Multipartite Entanglement Detection with Imperfect Measurements: Concept and Experiment

Area of Science:

• Quantum Information Science
• Experimental Quantum Physics
• Quantum Entanglement

Background:

• Standard entanglement detection relies on precise quantum measurements, which are difficult to achieve in practice.
• Measurement imperfections can lead to erroneous conclusions about genuine multipartite entanglement.

Purpose of the Study:

• To investigate the detection of genuine multipartite entanglement under realistic conditions with imperfect quantum measurements.
• To develop novel multipartite entanglement witnesses resilient to measurement errors.
• To experimentally validate the developed witnesses and correction analysis.

Main Methods:

• Theoretical construction of multipartite entanglement witnesses with imperfection-independent influence.
• Experimental implementation using a tabletop four-partite photonic setup.
• Analysis of measurement alignment errors and their impact on entanglement detection.

Main Results:

• Small alignment errors can significantly compromise standard entanglement detection.
• The developed entanglement witnesses demonstrate robustness against measurement imperfections.
• Correction analysis successfully mitigates the effects of experimental errors.

Conclusions:

• The study provides a practical framework for detecting multipartite entanglement in the presence of measurement imperfections.
• The developed witnesses offer enhanced noise resilience compared to device-independent models.
• This work advances the reliable characterization of complex quantum states in realistic experimental settings.