Experimental Measurement-Device-Independent Verification of Continuous-Variable Entanglement.

Quantum entanglement serves as an essential resource for quantum information technology. In many realistic quantum information tasks, it is necessary to reliably verify entanglement even when the measurement devices are unreliable. In this Letter, we experimentally demonstrate measurement-device-independent verification of continuous-variable (CV) entanglement. We show that the conventional CV entanglement witness may falsely identify a separable state as a CV entangled state when the measurement devices are unreliable. To eliminate such need for trusted measurement devices, we implement a measurement-device-independent entanglement witness for verifying CV entanglement and demonstrate its resilience against local oscillator power and phase modifications. Our Letter sheds light on advancing high-security quantum information processing and its practical implementation in quantum networks.