Certification of local quantum systems: Self-testing and dimension witnesses

Zapraszamy w środę 27.01.2021 o godz. 14:00 na seminarium.

Seminarium ONLINE pod tytułem: "Certification of local quantum systems: Self-testing and dimension witnesses" poprowadzi  Maharshi Ray (Centre for Quantum Technologies, National University of Singapore)

Abstract: We discuss schemes to certify local quantum systems via self-testing and dimension witnessing. This work leverages the graph-theoretic framework for contextuality introduced by Cabello, Severini, and Winter, combined with tools from combinatorial optimisation that guarantee the unicity of optimal solutions. We first show that the celebrated Klyachko-Can-Binicioglu-Shumovsky inequality and its generalisation to contextuality scenarios with odd cycle compatibility relations admit robust self-testing. We extend this robust self-testing result to the class of contextuality scenarios with odd anti-cycle compatibility structure which enables us to self-test arbitrary high dimensional quantum systems. Dimension witnessing is another tool for device certification where the goal is to certify the underlying dimensions of the quantum systems just from the measurement statistics. We present the concepts and tools needed for graph-theoretic quantum dimension witnessing and illustrate their use by identifying quantum dimension witnesses, including a family that can certify arbitrarily high quantum dimensions with few events.