Experimental test of noncontextuality inequality without causal chain assumptions

Contextuality and entanglement are fundamental quantum resources for quantum information processing, and contextuality has been identified as a necessary precondition for entanglement. However, direct implementation of this connection in a realistic experiment remains to be demonstrated. In addition, previous experiments face practical challenges in explicitly satisfying the linear constraints required for contextuality tests. In this work, we present an experimental investigation of this relationship using polarization-entangled photons. First, remote state preparation arising from entanglement allows the required linear constraints to be satisfied structurally. Second, our results provide an operational demonstration of the relationship’s asymmetrical nature. While all four tested Bell states violate a general noncontextuality inequality, confirming they are all contextual resources, only a single Bell state violates the specific entanglement witness mapped from it. This work provides a proof-of-principle experimental implementation of the contextuality-entanglement connection and illustrates how remote state preparation can be used to realize the relevant linear constraints in this setting. Contextuality is a fundamental resource for quantum information processing, underpinning quantum entanglement. Here, the authors experimentally demonstrate the asymmetrical relationship between contextuality and entanglement using polarization-entangled photons, revealing the noninjective nature of their mapping and advancing methods to explore quantum properties.