Measurement-Device-Independent Verification of Quantum Channels
Francesco Graffitti, Alexander Pickston, Peter Barrow, Massimiliano Proietti, Dmytro Kundys, Denis Rosset, Martin Ringbauer, Alessandro Fedrizzi
Abstract
The capability to reliably transmit and store quantum information is an essential building block for future quantum networks and processors. Gauging the ability of a communication link or quantum memory to preserve quantum correlations is therefore vital for their technological application. Here, we experimentally demonstrate a measurement-device-independent protocol for certifying that an unknown channel acts as an entanglement-preserving channel. Our results show that, even under realistic experimental conditions, including imperfect single-photon sources and the various kinds of noise-in the channel or in detection-where other verification means would fail or become inefficient, the present verification protocol is still capable of affirming the quantum behavior in a faithful manner with minimal trust on the measurement device.