Demonstrating the power of quantum computers, certification of highly entangled measurements and scalable quantum nonlocality

TL;DR

This paper showcases how advanced IBM quantum computers can perform complex correlation experiments, certifying entanglement and nonlocality in multi-qubit systems, thus highlighting their potential in quantum certification and network applications.

Contribution

It demonstrates the use of IBM quantum computers for certifying scalable entangled measurements and quantum nonlocality in multi-qubit systems, advancing quantum certification methods.

Findings

Quantum correlations defy classical models in up to nine qubits.

Certified 82 entangled basis elements in a 512-outcome measurement.

Reported violations of source-independent Bell inequalities up to ten qubits.

Abstract

Increasingly sophisticated quantum computers motivate the exploration of their abilities in certifying genuine quantum phenomena. Here, we demonstrate the power of state-of-the-art IBM quantum computers in correlation experiments inspired by quantum networks. Our experiments feature up to 12 qubits and require the implementation of paradigmatic Bell-State Measurements for scalable entanglement-swapping. First, we demonstrate quantum correlations that defy classical models in up to nine-qubit systems while only assuming that the quantum computer operates on qubits. Harvesting these quantum advantages, we are able to certify 82 basis elements as entangled in a 512-outcome measurement. Then, we relax the qubit assumption and consider quantum nonlocality in a scenario with multiple independent entangled states arranged in a star configuration. We report quantum violations of source-independent Bell inequalities for up to ten qubits. Our results demonstrate the ability of quantum computers to outperform classical limitations and certify scalable entangled measurements.