Talk on "Device-independent certification of quantum protocols" by Iris Agresti (Uni Roma)


The design of new technologies based on quantum effects, within the last years, has impacted a great variety of fields. For this reason, it is crucial to be endowed with techniques to distinguish devices that actually display a quantum resource-based functioning from those that do not. To tackle this non-trivial task, it is convenient to rely only on input/output statistics, without the need of a perfect knowledge of the inner functioning of the device, since this may be hard to verify or simply unknown to the user. This approach is called device-independent and it is typically based on the quantum violation of Bell inequalities. However, to detect the presence of different kinds of non-classical correlations and in view of the realization of quantum communication networks involving more than two parties, it is pivotal to take a step further from this standard scenario and study different processes.


In such a context, this talk will deal with the design and implementation on a photonic platform of device-independent protocols for alternative venues, with respect to Bell’s one. In particular, at first, we consider a certified quantum randomness generation protocol based on the violation of the so-called instrumental inequalities, featuring an unknown state shared by two parties, connected by a classical communication channel. The security of this protocol against any adversarial attack is established through the application of the Entropy Accumulation Theorem. Then, we present a self-testing protocol aiming to provide fidelity lower bounds of the state generated by two basic quantum networks with respect to a given target. This protocol also allows to lower bound the entanglement dimension of the state.


Friday, 5th of March 2021






Hosted by: Philip Walther