KVS Shiv Chaitanya

Hardy’s non-locality provides a proof of the incompatibility between quantum mechanics and local realism without using Bell inequalities. While this argument has been extensively studied for two- and three-qubit systems, a detailed analysis of the four-qubit case is still lacking. In this work, we investigate Hardy’s non-locality for a four-qubit system within the standard two-setting framework. We explicitly construct the entangled state satisfying the Hardy conditions and determine the measurement settings that maximize the success probability. Furthermore, we extend the analysis to multipartite qubit systems and investigate how the Hardy success probability behaves as the number of qubits increases. The results indicate a monotonic increase of the Hardy success probability for larger multipartite systems.