Testing tripartite Mermin inequalities by spectral joint-measurements of qubits

TL;DR

This paper proposes a scheme using spectral joint-measurements of qubits to generate a GHZ state and test the tripartite Mermin inequality, demonstrating feasibility through numerical simulations.

Contribution

It introduces a novel method for generating GHZ states and testing tripartite Bell inequalities via spectral joint-measurements in a cavity-QED setup.

Findings

Successful one-step GHZ state generation

Direct confirmation of tripartite entanglement

Feasibility demonstrated through numerical experiments

Abstract

It is well known that Bell inequality supporting the local realism can be violated in quantum mechanics. Numerous tests of such a violation have been demonstrated with bipartite entanglements. Using spectral jointmeasurements of the qubits, we here propose a scheme to test the tripartite Mermin inequality (a three-qubit Bell-type inequality) with three qubits dispersively-coupled to a driven cavity. First, we show how to generate a three-qubit Greenberger-Horne-Zeilinger (GHZ) state by only one-step quantum operation. Then, spectral joint-measurements are introduced to directly confirm such a tripartite entanglement. Assisted by a series of single-qubit operations, these measurements are further utilized to test the Mermin inequality. The feasibility of the proposal is robustly demonstrated by the present numerical experiments.