Hidden variables in Mermin GHZ machine with quantum assistance

TL;DR

This paper reports experiments on a three-qubit GHZ-like state using IBM quantum computers, revealing violations of Mermin's inequality and exploring how hidden variables and assistant qubits influence the interpretation of quantum correlations.

Contribution

It introduces a novel experimental setup with assistant qubits that affect the interpretation of hidden variables in GHZ experiments.

Findings

Violation of Mermin's inequality observed.

Hidden variables may be non-local depending on initialization.

Assistant qubits influence the interpretation of quantum correlations.

Abstract

Three experiments, with an IBM superconducting quantum computer, are presented, where the setting combinations on a three qubit GHZ(like) state were selected by two additional assistant qubits. The average of the polynomial of Mermin for the three entangled qubits was calculated; the results showed violation of the inequality of Mermin. However, given that the assistant qubits selected, imposed and informed the type of settings, it was possible to interpret the results in terms of arranged relations among hidden variables of the assistants and the entanglement BEFORE each shot; the hidden variables may or may not be local depending on the way the qubits were initialized.