# Measurement Device Independent Verification of Quantum Channels

## TL;DR

This paper presents an experimental measurement-device-independent protocol to verify that quantum channels preserve entanglement, ensuring reliable quantum communication even with imperfect sources and noise.

## Contribution

It introduces a novel verification method that does not rely on trusted measurement devices, suitable for realistic noisy quantum systems.

## Key findings

- Successfully verified entanglement-preserving channels under realistic conditions
- Demonstrated robustness against noise and device imperfections
- Validated the protocol's effectiveness in practical quantum networks

## 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 behaviour in a faithful manner without requiring any trust on the measurement device.