Self-testing and certification using trusted quantum inputs

TL;DR

This paper explores the use of trusted quantum inputs for self-testing and certification of quantum devices, establishing protocols that relate to fundamental quantum tasks and applying them to quantum networks.

Contribution

It introduces new self-testing protocols using trusted quantum inputs and connects these methods to basic quantum information tasks like teleportation and network quality assessment.

Findings

Developed self-testing protocols with trusted quantum inputs

Linked self-testing to quantum teleportation and network evaluation

Provided methods for estimating quantum network quality

Abstract

Device-independent certification of quantum devices is of crucial importance for the development of secure quantum information protocols. So far, the most studied scenario corresponds to a system consisting of different non-characterized devices that observers probe with classical inputs to obtain classical outputs. The certification of relevant quantum properties follows from the observation of correlations between these events that do not have a classical counterpart. In the fully device-independent scenario no assumptions are made on the devices and therefore their non-classicality follows from Bell non-locality. There exist other scenarios, known as semidevice-independent, in which assumptions are made on the devices, such as their dimension, and non-classicality is associated to the observation of other types of correlations with no classical analogue. More recently, the use of trusted quantum inputs for certification has been introduced. The goal of this work is to study the power of this formalism and describe self-testing protocols in various settings using trusted quantum inputs. We also relate these different types of self-testing to some of the most basic quantum information protocols, such as quantum teleportation. Finally, we apply our findings to quantum networks and provide methods for estimating the quality of the whole network, as well as of parts of it.