Mermin's inequalities of multiple qubits with orthogonal measurements on<scp>IBM</scp>Q 53‐qubit system
Wei‐Jia Huang, Wei‐Chen Chien, Chien‐Hung Cho, Che‐Chun Huang, Tsung‐Wei Huang, Ching‐Ray Chang
Abstract
Entanglement properties of IBM Q 53-qubit quantum computer are carefully examined with the noisy intermediate-scale quantum technology. We study Greenberger-Horne-Zeilinger-like states with multiple qubits (N = 2 to N = 7) on IBM Rochester and compare their maximal violation values of Mermin's polynomials with analytic results. A rule of N-qubits orthogonal measurements is taken to further justify the entanglement less than maximal values of local realism. The orthogonality of measurements is another reliable criterion for entanglement except the maximal values of LR. Our results indicate that the entanglement of IBM 53 qubits is reasonably good when N ≤ 4, while for the longer entangle chains, the entanglement is only valid for some special connectivity.