Biography
Ivan Šupić is a CNRS researcher at the University Grenoble Alpes. Previously, he held a postdoctoral position at Sorbonne University (LIP6) and at the University of Geneva, and completed his PhD at ICFO Barcelona. His research focuses on the certification of quantum resources, in particular self-testing and device-independent quantum information processing, as well as their connections to quantum cryptography and quantum foundations.
Abstract
How much can we learn about a quantum system by only looking at its measurement statistics, without making any assumptions about its inner workings? Self-testing provides a striking answer: in certain scenarios, the observed correlations alone are enough to completely determine the underlying quantum state and measurements, up to local isometries. Born in quantum cryptography through the pioneering work of Mayers and Yao, who showed that the security of certain protocols could be guaranteed even with completely untrusted devices, self-testing has since grown into one of the most versatile tools in quantum information theory. It is closely connected to the theoretical foundations of device-independent quantum key distribution and randomness generation, and has found remarkable applications in theoretical computer science: from delegated quantum computation and proofs of quantumness to various quantum complexity results, including the landmark MIP*=RE theorem. In this tutorial, I will introduce the concept of self-testing from the ground up, take a guided tour through its most important applications, from its cryptographic origins to its far-reaching implications in computer science, and then unpack the main techniques used to prove self-testing results.